Author name code: suematsu
ADS astronomy entries on 2022-09-14
author:"Suematsu, Yoshinori" 
------------------------------------------------------------------------  

Title: Quiet Sun Center to Limb Variation of the Linear Polarization
    Observed by CLASP2 Across the Mg II h and k Lines
Authors: Rachmeler, L. A.; Bueno, J. Trujillo; McKenzie, D. E.;
   Ishikawa, R.; Auchère, F.; Kobayashi, K.; Kano, R.; Okamoto,
   T. J.; Bethge, C. W.; Song, D.; Ballester, E. Alsina; Belluzzi,
   L.; Pino Alemán, T. del; Ramos, A. Asensio; Yoshida, M.; Shimizu,
   T.; Winebarger, A.; Kobelski, A. R.; Vigil, G. D.; Pontieu, B. De;
   Narukage, N.; Kubo, M.; Sakao, T.; Hara, H.; Suematsu, Y.; Štěpán,
   J.; Carlsson, M.; Leenaarts, J.
Bibcode: 2022ApJ...936...67R
Altcode: 2022arXiv220701788R
  The CLASP2 (Chromospheric LAyer Spectro-Polarimeter 2) sounding rocket
  mission was launched on 2019 April 11. CLASP2 measured the four Stokes
  parameters of the Mg II h and k spectral region around 2800 Å along a
  200″ slit at three locations on the solar disk, achieving the first
  spatially and spectrally resolved observations of the solar polarization
  in this near-ultraviolet region. The focus of the work presented here
  is the center-to-limb variation of the linear polarization across these
  resonance lines, which is produced by the scattering of anisotropic
  radiation in the solar atmosphere. The linear polarization signals of
  the Mg II h and k lines are sensitive to the magnetic field from the
  low to the upper chromosphere through the Hanle and magneto-optical
  effects. We compare the observations to theoretical predictions
  from radiative transfer calculations in unmagnetized semiempirical
  models, arguing that magnetic fields and horizontal inhomogeneities
  are needed to explain the observed polarization signals and spatial
  variations. This comparison is an important step in both validating and
  refining our understanding of the physical origin of these polarization
  signatures, and also in paving the way toward future space telescopes
  for probing the magnetic fields of the solar upper atmosphere via
  ultraviolet spectropolarimetry.

Title: Mapping of Solar Magnetic Fields from the Photosphere to the
    Top of the Chromosphere with CLASP2
Authors: McKenzie, D.; Ishikawa, R.; Trujillo Bueno, J.; Auchere, F.;
   del Pino Aleman, T.; Okamoto, T.; Kano, R.; Song, D.; Yoshida, M.;
   Rachmeler, L.; Kobayashi, K.; Narukage, N.; Kubo, M.; Ishikawa, S.;
   Hara, H.; Suematsu, Y.; Sakao, T.; Bethge, C.; De Pontieu, B.; Vigil,
   G.; Winebarger, A.; Alsina Ballester, E.; Belluzzi, L.; Stepan, J.;
   Asensio Ramos, A.; Carlsson, M.; Leenaarts, J.
Bibcode: 2021AAS...23810603M
Altcode:
  Coronal heating, chromospheric heating, and the heating &amp;
  acceleration of the solar wind, are well-known problems in solar
  physics. Additionally, knowledge of the magnetic energy that
  powers solar flares and coronal mass ejections, important drivers
  of space weather, is handicapped by imperfect determination of the
  magnetic field in the sun's atmosphere. Extrapolation of photospheric
  magnetic measurements into the corona is fraught with difficulties and
  uncertainties, partly due to the vastly different plasma beta between
  the photosphere and the corona. Better results in understanding
  the coronal magnetic field should be derived from measurements of
  the magnetic field in the chromosphere. To that end, we are pursuing
  quantitative determination of the magnetic field in the chromosphere,
  where plasma beta transitions from greater than unity to less than
  unity, via ultraviolet spectropolarimetry. The CLASP2 mission, flown
  on a sounding rocket in April 2019, succeeded in measuring all four
  Stokes polarization parameters in UV spectral lines formed by singly
  ionized Magnesium and neutral Manganese. Because these ions produce
  spectral lines under different conditions, CLASP2 thus was able to
  quantify the magnetic field properties at multiple heights in the
  chromosphere simultaneously, as shown in the recent paper by Ishikawa
  et al. In this presentation we will report the findings of CLASP2,
  demonstrating the variation of magnetic fields along a track on
  the solar surface and as a function of height in the chromosphere;
  and we will illustrate what is next for the CLASP missions and the
  demonstration of UV spectropolarimetry in the solar chromosphere.

Title: Instrumental design of the Solar Observing Satellite:
    solar-C_EUVST
Authors: Suematsu, Yoshinori; Shimizu, Toshifumi; Hara, Hirohisa;
   Kawate, Tomoko; Katsukawa, Yukio; Ichimoto, Kiyoshi; Imada, Shinsuke
Bibcode: 2021SPIE11852E..3KS
Altcode:
  The EUV High-Throughput Spectroscopic Telescope (EUVST) of Solar-C
  mission is a revolutionary spectrometer that is designed to provide
  high-quality and high cadence spectroscopic data covering a wide
  temperature range of the chromosphere to flaring corona to investigate
  the energetics and dynamics of the solar atmosphere. The EUVST consists
  of only two imaging optical components; a 28-cm clear aperture off-axis
  parabolic primary mirror and a two-split ellipsoidal grating without a
  blocking filter for visible light before the primary mirror to achieve
  unprecedented high spatial and temporal resolution in EUV-UV imaging
  spectroscopic observations. For this reason, about 53 W of sunlight
  is absorbed by the multilayer coating on the mirror. We present an
  instrumental design of the telescope, particularly, primary mirror
  assembly which enables slit-scan observations for imaging spectroscopy,
  an image stabilizing tip-tilt control, and a focus adjustment on
  orbit, together with an optomechanical design of the primary mirror
  and its supporting system which gives optically tolerant wavefront
  error against a large temperature increase due to an absorption of
  visible and IR lights.

Title: Critical Science Plan for the Daniel K. Inouye Solar Telescope
    (DKIST)
Authors: Rast, Mark P.; Bello González, Nazaret; Bellot Rubio,
   Luis; Cao, Wenda; Cauzzi, Gianna; Deluca, Edward; de Pontieu, Bart;
   Fletcher, Lyndsay; Gibson, Sarah E.; Judge, Philip G.; Katsukawa,
   Yukio; Kazachenko, Maria D.; Khomenko, Elena; Landi, Enrico; Martínez
   Pillet, Valentín; Petrie, Gordon J. D.; Qiu, Jiong; Rachmeler,
   Laurel A.; Rempel, Matthias; Schmidt, Wolfgang; Scullion, Eamon; Sun,
   Xudong; Welsch, Brian T.; Andretta, Vincenzo; Antolin, Patrick; Ayres,
   Thomas R.; Balasubramaniam, K. S.; Ballai, Istvan; Berger, Thomas E.;
   Bradshaw, Stephen J.; Campbell, Ryan J.; Carlsson, Mats; Casini,
   Roberto; Centeno, Rebecca; Cranmer, Steven R.; Criscuoli, Serena;
   Deforest, Craig; Deng, Yuanyong; Erdélyi, Robertus; Fedun, Viktor;
   Fischer, Catherine E.; González Manrique, Sergio J.; Hahn, Michael;
   Harra, Louise; Henriques, Vasco M. J.; Hurlburt, Neal E.; Jaeggli,
   Sarah; Jafarzadeh, Shahin; Jain, Rekha; Jefferies, Stuart M.; Keys,
   Peter H.; Kowalski, Adam F.; Kuckein, Christoph; Kuhn, Jeffrey R.;
   Kuridze, David; Liu, Jiajia; Liu, Wei; Longcope, Dana; Mathioudakis,
   Mihalis; McAteer, R. T. James; McIntosh, Scott W.; McKenzie, David
   E.; Miralles, Mari Paz; Morton, Richard J.; Muglach, Karin; Nelson,
   Chris J.; Panesar, Navdeep K.; Parenti, Susanna; Parnell, Clare E.;
   Poduval, Bala; Reardon, Kevin P.; Reep, Jeffrey W.; Schad, Thomas A.;
   Schmit, Donald; Sharma, Rahul; Socas-Navarro, Hector; Srivastava,
   Abhishek K.; Sterling, Alphonse C.; Suematsu, Yoshinori; Tarr, Lucas
   A.; Tiwari, Sanjiv; Tritschler, Alexandra; Verth, Gary; Vourlidas,
   Angelos; Wang, Haimin; Wang, Yi-Ming; NSO and DKIST Project; DKIST
   Instrument Scientists; DKIST Science Working Group; DKIST Critical
   Science Plan Community
Bibcode: 2021SoPh..296...70R
Altcode: 2020arXiv200808203R
  The National Science Foundation's Daniel K. Inouye Solar Telescope
  (DKIST) will revolutionize our ability to measure, understand,
  and model the basic physical processes that control the structure
  and dynamics of the Sun and its atmosphere. The first-light DKIST
  images, released publicly on 29 January 2020, only hint at the
  extraordinary capabilities that will accompany full commissioning of
  the five facility instruments. With this Critical Science Plan (CSP)
  we attempt to anticipate some of what those capabilities will enable,
  providing a snapshot of some of the scientific pursuits that the DKIST
  hopes to engage as start-of-operations nears. The work builds on the
  combined contributions of the DKIST Science Working Group (SWG) and
  CSP Community members, who generously shared their experiences, plans,
  knowledge, and dreams. Discussion is primarily focused on those issues
  to which DKIST will uniquely contribute.

Title: Mapping solar magnetic fields from the photosphere to the
    base of the corona
Authors: Ishikawa, Ryohko; Bueno, Javier Trujillo; del Pino Alemán,
   Tanausú; Okamoto, Takenori J.; McKenzie, David E.; Auchère,
   Frédéric; Kano, Ryouhei; Song, Donguk; Yoshida, Masaki; Rachmeler,
   Laurel A.; Kobayashi, Ken; Hara, Hirohisa; Kubo, Masahito; Narukage,
   Noriyuki; Sakao, Taro; Shimizu, Toshifumi; Suematsu, Yoshinori; Bethge,
   Christian; De Pontieu, Bart; Dalda, Alberto Sainz; Vigil, Genevieve D.;
   Winebarger, Amy; Ballester, Ernest Alsina; Belluzzi, Luca; Štěpán,
   Jiří; Ramos, Andrés Asensio; Carlsson, Mats; Leenaarts, Jorrit
Bibcode: 2021SciA....7.8406I
Altcode: 2021arXiv210301583I
  Routine ultraviolet imaging of the Sun's upper atmosphere shows the
  spectacular manifestation of solar activity; yet we remain blind to
  its main driver, the magnetic field. Here we report unprecedented
  spectropolarimetric observations of an active region plage and
  its surrounding enhanced network, showing circular polarization in
  ultraviolet (Mg II $h$ &amp; $k$ and Mn I) and visible (Fe I) lines. We
  infer the longitudinal magnetic field from the photosphere to the
  very upper chromosphere. At the top of the plage chromosphere the
  field strengths reach more than 300 gauss, strongly correlated with
  the Mg II $k$ line core intensity and the electron pressure. This
  unique mapping shows how the magnetic field couples the different
  atmospheric layers and reveals the magnetic origin of the heating in
  the plage chromosphere.

Title: Chromospheric Heating Associated with Strong Photospheric
    Downflow Events in Photospheric Flux Tubes
Authors: Suematsu, Yoshinori
Bibcode: 2021cosp...43E1800S
Altcode:
  The formation of small-scale strong magnetic features in the quiet
  Sun was studied for a long time. It is likely that magnetic field
  on the solar surface is collected in the intergranular lanes by
  the horizontal flows in granules, and then a convective instability
  (collapse), which leads to downflow in the flux tube and a reduction
  of the internal gas pressure, intensifies them to kG levels. However,
  a static equilibrium with such a strong field would not be realized
  and open question remained is the evolution including the possible
  rebounding upflow and the associated chromospheric responses, which
  may show up as shocks and subsequent heating. Using high resolution
  time series of Hinode/SOT filter images in Na D1 line, G-band and Ca
  II H band at the quiet Sun disk center, we were able to identify many
  point-like downflow (convective collapse) events in the photosphere
  and corresponding chromospheric bright points. For each events,
  we investigated temporal variations of, photospheric vertical flow
  velocities, magnetic flux, G-band intensity (proxy of kG field) and
  Ca II H intensity (chromospheric brightening) to see the implications
  of convective collapse on the photospheric and chromospheric dynamical
  processes.In 500 point-like downflow events studied, most cases indicate
  a signature of convective collapse (G-band brightening). Typical
  lifetime of downflow is about a few minutes Irrespective of strength
  of magnetic flux, strong downflows are always associated with Ca II
  H bright points which appear about a minute later, implying a rebound
  shock heating of the low chromosphere.

Title: Sunrise Chromospheric Infrared spectroPolarimeter (SCIP)
for SUNRISE III: optical design and performance
Authors: Tsuzuki, Toshihiro; Katsukawa, Yukio; Uraguchi, Fumihiro;
   Hara, Hirohisa; Kubo, Masahito; Nodomi, Yoshifumi; Suematsu, Yoshinori;
   Kawabata, Yusuke; Shimizu, Toshifumi; Gandorfer, Achim; Feller, Alex;
   Grauf, Bianca; Solanki, Sami; Carlos del Toro Iniesta, Jose
Bibcode: 2020SPIE11447E..AJT
Altcode:
  The Sunrise Chromospheric Infrared spectroPolarimeter (SCIP) is a
  near-IR spectro-polarimeter instrument newly designed for Sunrise III,
  which is a balloon-borne solar observatory equipped with a 1 m optical
  telescope. To acquire high-quality 3D magnetic and velocity fields,
  SCIP selects the two wavelength bands centered at 850 nm and 770 nm,
  which contain many spectrum lines that are highly sensitive to magnetic
  fields permeating the photosphere and chromosphere. To achieve high
  spatial and spectral resolution (0.21 arcsec and 2 × 10<SUP>5</SUP>),
  SCIP optics adopt a quasi-Littrow configuration based on an echelle
  grating and two high-order aspheric mirrors. Using different diffraction
  orders of the echelle grating, dichroic beam splitter, and polarizing
  beam-splitters, SCIP can obtain s- and p-polarization signals in the
  two wavelength bands simultaneously within a relatively small space. We
  established the wavefront error budget based on tolerance analysis,
  surface figure errors, alignment errors, and environmental changes. In
  addition, we performed stray light analysis, and designed light traps
  and baffles needed to suppress unwanted reflections and diffraction
  by the grating. In this paper, we present the details of this optical
  system and its performance.

Title: Sunrise Chromospheric Infrared spectroPolarimeter (SCIP)
for SUNRISE III: opto-mechanical analysis and design
Authors: Uraguchi, Fumihiro; Tsuzuki, Toshihiro; Katsukawa, Yukio;
   Hara, Hirohisa; Iwamura, Satoru; Kubo, Masahito; Nodomi, Yoshifumi;
   Suematsu, Yoshinori; Kawabata, Yusuke; Shimizu, Toshifumi; Gandorfer,
   Achim; del Toro Iniesta, Jose Carlos
Bibcode: 2020SPIE11447E..ABU
Altcode:
  The Sunrise Chromospheric Infrared spectroPolarimeter (SCIP) is a
  near-IR spectro-polarimeter instrument newly designed for Sunrise III,
  a balloon-borne solar observatory with a 1-m diameter telescope. In
  order to achieve the strict requirements the SCIP wavefront error, it is
  necessary to quantify the errors due to environmen- tal effects such as
  gravity and temperature variation under the observation conditions. We
  therefore conducted an integrated opto-mechanical analysis incorporating
  mechanical and thermal disturbances into a finite element model of
  the entire SCIP structure to acquire the nodal displacements of each
  optical element, then fed them back to the optical analysis software
  in the form of rigid body motion and surface deformation fitted by
  polynomials. This method allowed us to determine the error factors
  having a significant influence on optical performance. For example,
  no significant wavefront degradation was associated with the structural
  mountings because the optical element mounts were well designed based
  on quasi-kinematic constraints. In contrast, we found that the main
  factor affecting wavefront degradation was the rigid body motions of
  the optical elements, which must be mini- mized within the allowable
  level. Based on these results, we constructed the optical bench using a
  sandwich panel as the optical bench consisting of an aluminum-honeycomb
  core and carbon fiber reinforced plastic skins with a high stiffness
  and low coefficient of thermal expansion. We then confirmed that the
  new opto-mechanical model achieved the wavefront error requirement. In
  this paper, we report the details of this integrated opto-mechanical
  analysis, including the wavefront error budgeting and the design of
  the opto-mechanics.

Title: The Solar-C (EUVST) mission: the latest status
Authors: Shimizu, Toshifumi; Imada, Shinsuke; Kawate, Tomoko; Suematsu,
   Yoshinori; Hara, Hirohisa; Tsuzuki, Toshihiro; Katsukawa, Yukio; Kubo,
   Masahito; Ishikawa, Ryoko; Watanabe, Tetsuya; Toriumi, Shin; Ichimoto,
   Kiyoshi; Nagata, Shin'ichi; Hasegawa, Takahiro; Yokoyama, Takaaki;
   Watanabe, Kyoko; Tsuno, Katsuhiko; Korendyke, Clarence M.; Warren,
   Harry; De Pontieu, Bart; Boerner, Paul; Solanki, Sami K.; Teriaca,
   Luca; Schuehle, Udo; Matthews, Sarah; Long, David; Thomas, William;
   Hancock, Barry; Reid, Hamish; Fludra, Andrzej; Auchère, Frederic;
   Andretta, Vincenzo; Naletto, Giampiero; Poletto, Luca; Harra, Louise
Bibcode: 2020SPIE11444E..0NS
Altcode:
  Solar-C (EUVST) is the next Japanese solar physics mission to
  be developed with significant contributions from US and European
  countries. The mission carries an EUV imaging spectrometer with
  slit-jaw imaging system called EUVST (EUV High-Throughput Spectroscopic
  Telescope) as the mission payload, to take a fundamental step towards
  answering how the plasma universe is created and evolves and how the
  Sun influences the Earth and other planets in our solar system. In
  April 2020, ISAS (Institute of Space and Astronautical Science) of JAXA
  (Japan Aerospace Exploration Agency) has made the final down-selection
  for this mission as the 4th in the series of competitively chosen
  M-class mission to be launched with an Epsilon launch vehicle in mid
  2020s. NASA (National Aeronautics and Space Administration) has selected
  this mission concept for Phase A concept study in September 2019 and
  is in the process leading to final selection. For European countries,
  the team has (or is in the process of confirming) confirmed endorsement
  for hardware contributions to the EUVST from the national agencies. A
  recent update to the mission instrumentation is to add a UV spectral
  irradiance monitor capability for EUVST calibration and scientific
  purpose. This presentation provides the latest status of the mission
  with an overall description of the mission concept emphasizing on key
  roles of the mission in heliophysics research from mid 2020s.

Title: Sunrise Chromospheric Infrared SpectroPolarimeter (SCIP)
for sunrise III: system design and capability
Authors: Katsukawa, Y.; del Toro Iniesta, J. C.; Solanki, S. K.;
   Kubo, M.; Hara, H.; Shimizu, T.; Oba, T.; Kawabata, Y.; Tsuzuki,
   T.; Uraguchi, F.; Nodomi, Y.; Shinoda, K.; Tamura, T.; Suematsu,
   Y.; Ishikawa, R.; Kano, R.; Matsumoto, T.; Ichimoto, K.; Nagata, S.;
   Quintero Noda, C.; Anan, T.; Orozco Suárez, D.; Balaguer Jiménez,
   M.; López Jiménez, A. C.; Cobos Carrascosa, J. P.; Feller, A.;
   Riethmueller, T.; Gandorfer, A.; Lagg, A.
Bibcode: 2020SPIE11447E..0YK
Altcode:
  The Sunrise balloon-borne solar observatory carries a 1 m aperture
  optical telescope and provides us a unique platform to conduct
  continuous seeing-free observations at UV-visible-IR wavelengths from
  an altitude of higher than 35 km. For the next flight planned for
  2022, the post-focus instrumentation is upgraded with new spectro-
  polarimeters for the near UV (SUSI) and the near-IR (SCIP), whereas
  the imaging spectro-polarimeter Tunable Magnetograph (TuMag) is capable
  of observing multiple spectral lines within the visible wavelength. A
  new spectro-polarimeter called the Sunrise Chromospheric Infrared
  spectroPolarimeter (SCIP) is under development for observing near-IR
  wavelength ranges of around 770 nm and 850 nm. These wavelength ranges
  contain many spectral lines sensitive to solar magnetic fields and
  SCIP will be able to obtain magnetic and velocity structures in the
  solar atmosphere with a sufficient height resolution by combining
  spectro-polarimetric data of these lines. Polarimetric measurements are
  conducted using a rotating waveplate as a modulator and polarizing beam
  splitters in front of the cameras. The spatial and spectral resolutions
  are 0.2" and 2 105, respectively, and a polarimetric sensitivity of
  0.03 % (1σ) is achieved within a 10 s integration time. To detect
  minute polarization signals with good precision, we carefully designed
  the opto-mechanical system, polarization optics and modulation, and
  onboard data processing.

Title: Current Status of the Solar-C_EUVST Mission
Authors: Imada, S.; Shimizu, T.; Kawate, T.; Toriumi, S.; Katsukawa,
   Y.; Kubo, M.; Hara, H.; Suematsu, Y.; Ichimoto, K.; Watanabe, T.;
   Watanabe, K.; Yokoyama, T.; Warren, H.; Long, D.; Harra, L. K.;
   Teriaca, L.
Bibcode: 2020AGUFMSH056..05I
Altcode:
  Solar-C_EUVST (EUV High-Throughput Spectroscopic Telescope) is designed
  to comprehensively understand the energy and mass transfer from the
  solar surface to the solar corona and interplanetary space, and to
  investigate the elementary processes that take place universally
  in cosmic plasmas. As a fundamental step towards answering how the
  plasma universe is created and evolves, and how the Sun influences
  the Earth and other planets in our solar system, the proposed mission
  is designed to comprehensively understand how mass and energy are
  transferred throughout the solar atmosphere. Understanding the solar
  atmosphere, which connects to the heliosphere via radiation, the solar
  wind and coronal mass ejections, and energetic particles is pivotal
  for establishing the conditions for life and habitability in the solar
  system. <P />The two primary science objectives for Solar-C_EUVST are :
  I) Understand how fundamental processes lead to the formation of the
  solar atmosphere and the solar wind, II) Understand how the solar
  atmosphere becomes unstable, releasing the energy that drives solar
  flares and eruptions. Solar-C_EUVST will, A) seamlessly observe all
  the temperature regimes of the solar atmosphere from the chromosphere
  to the corona at the same time, B) resolve elemental structures of the
  solar atmosphere with high spatial resolution and cadence to track their
  evolution, and C) obtain spectroscopic information on the dynamics of
  elementary processes taking place in the solar atmosphere. <P />In this
  talk, we will first discuss the science target of the Solar-C_EUVST,
  and then discuss the current status of the Solar-C_EUVST mission.

Title: Thermal design of the Solar-C (EUVST) telescope
Authors: Suematsu, Yoshinori; Shimizu, Toshifumi; Hara, Hirohisa;
   Kawate, Tomoko; Katsukawa, Yukio; Ichimoto, Kiyoshi; Imada, Shinsuke;
   Nagae, Kazuhiro; Yamazaki, Atsumu; Hattori, Tomoya
Bibcode: 2020SPIE11444E..3KS
Altcode:
  The EUV High-Throughput Spectroscopic Telescope (EUVST) of Solar-C
  mission consists of only two imaging optical components; a 28-cm clear
  aperture off-axis parabolic primary mirror and a two-split ellipsoidal
  grating without a blocking filter for visible light before the primary
  mirror to achieve unprecedented high spatial and temporal resolution in
  EUV-UV imaging spectroscopic observations. For this reason, about 60
  W of sunlight is absorbed by the multilayer coating on the mirror. We
  report a thermal design of telescope in which the temperature of the
  primary mirror bonding part and underlying tip-tilt and slit-scanning
  mechanisms is well lower than a glass transition temperature of adhesive
  (about 60°C) and thermal deformation of the primary mirror is small,
  although it is non-negligibly small.

Title: A sensitivity analysis of the updated optical design for
    EUVST on the Solar-C mission
Authors: Kawate, Tomoko; Tsuzuki, Toshihiro; Shimizu, Toshifumi;
   Imada, Shinsuke; Katsukawa, Yukio; Hara, Hirohisa; Suematsu, Yoshinori;
   Ichimoto, Kiyoshi; Hattori, Tomoya; Narasaki, Shota; Warren, Harry P.;
   Teriaca, Luca; Korendyke, Clarence M.; Brown, Charles M.; Auchere,
   Frederic
Bibcode: 2020SPIE11444E..3JK
Altcode:
  The EUV high-throughput spectroscopic telescope (EUVST) onboard the
  Solar-C mission has the high spatial (0.4'') resolution over a wide
  wavelength range in the vacuum ultraviolet. To achieve high spatial
  resolution under a design constraint given by the JAXA Epsilon launch
  vehicle, we further update the optical design to secure margins
  needed to realize 0.4'' spatial resolution over a field of view of
  100''×100''. To estimate the error budgets of spatial and spectral
  resolutions due to installation and fabrication errors, we perform a
  sensitivity analysis for the position and orientation of each optical
  element and for the grating parameters by ray tracing with the Zemax
  software. We obtain point spread functions (PSF) for rays from 9
  fields and at 9 wavelengths on each detector by changing each parameter
  slightly. A full width at half maximum (FWHM) of the PSF is derived at
  each field and wavelength position as a function of the perturbation
  of each optical parameter. Assuming a mount system of each optical
  element and an error of each optical parameter, we estimate spatial
  and spectral resolutions by taking installation and fabrication errors
  into account. The results of the sensitivity analysis suggest that
  budgets of the total of optical design and the assembly errors account
  for 15% and 5.8% of our budgets of the spatial resolution in the long
  wavelength and short wavelength bands, respectively. On the other hand,
  the grating fabrication errors give a large degradation of spatial and
  spectral resolutions, and investigations of compensators are needed
  to relax the fabrication tolerance of the grating surface parameters.

Title: High-frequency Wave Propagation Along a Spicule Observed
    by CLASP
Authors: Yoshida, Masaki; Suematsu, Yoshinori; Ishikawa, Ryohko;
   Okamoto, Takenori J.; Kubo, Masahito; Kano, Ryouhei; Narukage,
   Noriyuki; Bando, Takamasa; Winebarger, Amy R.; Kobayashi, Ken;
   Trujillo Bueno, Javier; Auchère, Frédéric
Bibcode: 2019ApJ...887....2Y
Altcode:
  The Chromospheric Lyman-Alpha Spectro-Polarimeter (CLASP) sounding
  rocket experiment, launched in 2015 September, observed the hydrogen
  Lyα line (121.6 nm) in an unprecedented high temporal cadence of
  0.3 s. CLASP performed sit-and-stare observations of the quiet Sun
  near the limb for 5 minutes with a slit perpendicular to the limb
  and successfully captured an off-limb spicule evolving along the
  slit. The Lyα line is well suited for investigating how spicules
  affect the corona because it is sensitive to higher temperatures than
  other chromospheric lines, owing to its large optical thickness. We
  found high-frequency oscillations of the Doppler velocity with periods
  of 20-50 s and low-frequency oscillation of periods of ∼240 s on
  the spicule. From a wavelet analysis of the time sequence data of
  the Doppler velocity, in the early phase of the spicule evolution,
  we found that waves with a period of ∼30 s and a velocity amplitude
  of 2-3 km s<SUP>-1</SUP> propagated upward along the spicule with a
  phase velocity of ∼470 km s<SUP>-1</SUP>. In contrast, in the later
  phase, possible downward and standing waves with smaller velocity
  amplitudes were also observed. The high-frequency waves observed in
  the early phase of the spicule evolution would be related with the
  dynamics and the formation of the spicules. Our analysis enabled us to
  identify the upward, downward, and standing waves along the spicule
  and to obtain the velocity amplitude of each wave directly from the
  Doppler velocity for the first time. We evaluated the energy flux
  by the upward-propagating waves along the spicule, and discussed the
  impact to the coronal heating.

Title: Relationship between Point-like Photospheric Downflows and
    Convective Collapse Events Seen in Hinode/SOT
Authors: Suematsu, Y.
Bibcode: 2019AGUFMSH43E3384S
Altcode:
  The formation of small-scale strong magnetic features in the quiet Sun
  was studied for a long time. It is likely that magnetic field on the
  solar surface is collected in the intergranular lanes by the horizontal
  flows in granules, and then a convective instability (collapse), which
  leads to downflow in the flux tube and a reduction of the internal gas
  pressure, intensifies them to kG levels. However, a static equilibrium
  with such a strong field would not be realized and the open question
  remained is the evolution including the possible rebounding upflow
  and the associated chromospheric responses, which may show up as
  shocks and subsequent heating. Using high-resolution time series of
  Hinode/SOT filter images in Na D1 line and Ca II H band at the quiet
  Sun disk center, we were able to identify many point-like downflows in
  the photosphere and corresponding chromospheric bright points, which
  are not always associated with magnetic field intensifications. For
  each event, we determined the duration, photospheric vertical flow
  velocities, line-of-sight field strength increase and the signature of
  chromospheric brightening. We present the implications of point-like
  downflows on the photospheric and chromospheric dynamical processes.

Title: Achievements of Hinode in the first eleven years
Authors: Hinode Review Team; Al-Janabi, Khalid; Antolin, Patrick;
   Baker, Deborah; Bellot Rubio, Luis R.; Bradley, Louisa; Brooks,
   David H.; Centeno, Rebecca; Culhane, J. Leonard; Del Zanna, Giulio;
   Doschek, George A.; Fletcher, Lyndsay; Hara, Hirohisa; Harra,
   Louise K.; Hillier, Andrew S.; Imada, Shinsuke; Klimchuk, James A.;
   Mariska, John T.; Pereira, Tiago M. D.; Reeves, Katharine K.; Sakao,
   Taro; Sakurai, Takashi; Shimizu, Toshifumi; Shimojo, Masumi; Shiota,
   Daikou; Solanki, Sami K.; Sterling, Alphonse C.; Su, Yingna; Suematsu,
   Yoshinori; Tarbell, Theodore D.; Tiwari, Sanjiv K.; Toriumi, Shin;
   Ugarte-Urra, Ignacio; Warren, Harry P.; Watanabe, Tetsuya; Young,
   Peter R.
Bibcode: 2019PASJ...71R...1H
Altcode:
  Hinode is Japan's third solar mission following Hinotori (1981-1982)
  and Yohkoh (1991-2001): it was launched on 2006 September 22 and is in
  operation currently. Hinode carries three instruments: the Solar Optical
  Telescope, the X-Ray Telescope, and the EUV Imaging Spectrometer. These
  instruments were built under international collaboration with the
  National Aeronautics and Space Administration and the UK Science and
  Technology Facilities Council, and its operation has been contributed
  to by the European Space Agency and the Norwegian Space Center. After
  describing the satellite operations and giving a performance evaluation
  of the three instruments, reviews are presented on major scientific
  discoveries by Hinode in the first eleven years (one solar cycle long)
  of its operation. This review article concludes with future prospects
  for solar physics research based on the achievements of Hinode.

Title: ngGONG: The Next Generation GONG - A New Solar Synoptic
    Observational Network
Authors: Hill, Frank; Hammel, Heidi; Martinez-Pillet, Valentin; de
   Wijn, A.; Gosain, S.; Burkepile, J.; Henney, C. J.; McAteer, J.; Bain,
   H. M.; Manchester, W.; Lin, H.; Roth, M.; Ichimoto, K.; Suematsu, Y.
Bibcode: 2019BAAS...51g..74H
Altcode: 2019astro2020U..74H
  The white paper describes a next-generation GONG, a ground-based
  geographically distributed network of instrumentation to continually
  observe the Sun. This would provide data for solar magnetic field
  research and space weather forecasting, and would extend the time
  coverage of helioseismology.

Title: Development of Solar-C_EUVST structural design
Authors: Suematsu, Yoshinori; Shimizu, Toshifumi; Hara, Hirohisa;
   Katsukawa, Yukio; Kawate, Tomoko; Ichimoto, Kiyoshi; Imada, Shinsuke
Bibcode: 2019SPIE11118E..1OS
Altcode:
  The Solar-C_EUVST is a mission designed to provide high-quality solar
  spectroscopic data covering a wide temperature range of the chromosphere
  to flaring corona. To fulfill a high throughput requirement, the
  instrument consists of only two optical components; a 28-cm primary
  mirror and a segmented toroidal grating which have high reflective
  coatings in EUV-UV range. We present a mission payload structural
  design which accommodates long focal length optical components and
  a launcher condition/launch environment (JAXA Epsilon). We also
  present a mechanical design of primary mirror assembly which enables
  slit-scan observations, an image stabilizing tip-tilt control, and a
  focus adjustment on orbit, together with an optomechanical design of
  the primary mirror and its supporting system which gives optically
  tolerant wavefront error against a large temperature increase due to
  an absorption of visible and IR lights.

Title: Concept study of Solar-C_EUVST optical design
Authors: Kawate, Tomoko; Shimizu, Toshifumi; Imada, Shinsuke; Tsuzuki,
   Toshihiro; Katsukawa, Yukio; Hara, Hirohisa; Suematsu, Yoshinori;
   Ichimoto, Kiyoshi; Warren, Harry; Teriaca, Luca; Korendyke, Clarence
   M.; Brown, Charles
Bibcode: 2019SPIE11118E..1NK
Altcode:
  The main characteristics of Solar-C_EUVST are the high temporal and
  high spatial resolutions over a wide temperature coverage. In order
  to realize the instrument for meeting these scientific requirements
  under size constraints given by the JAXA Epsilon vehicle, we examined
  four-dimensional optical parameter space of possible solutions of
  geometrical optical parameters such as mirror diameter, focal length,
  grating magnification, and so on. As a result, we have identified
  the solution space that meets the EUVST science objectives and rocket
  envelope requirements. A single solution was selected and used to define
  the initial optical parameters for the concept study of the baseline
  architecture for defining the mission concept. For this solution, we
  optimized the grating and geometrical parameters by ray tracing of the
  Zemax software. Consequently, we found an optics system that fulfills
  the requirement for a 0.4" angular resolution over a field of view of
  100" (including margins) covering spectral ranges of 170-215, 463-542,
  557-637, 690-850, 925-1085, and 1115-1275 A. This design achieves an
  effective area 10 times larger than the Extreme-ultraviolet Imaging
  Spectrometer onboard the Hinode satellite, and will provide seamless
  observations of 4.2-7.2 log(K) plasmas for the first time. Tolerance
  analyses were performed based on the optical design, and the moving
  range and step resolution of focus mechanisms were identified. In
  the presentation, we describe the derivation of the solution space,
  optimization of the optical parameters, and show the results of ray
  tracing and tolerance analyses.

Title: The Solar-C_EUVST mission
Authors: Shimizu, Toshifumi; Imada, Shinsuke; Kawate, Tomoko;
   Ichimoto, Kiyoshi; Suematsu, Yoshinori; Hara, Hirohisa; Katsukawa,
   Yukio; Kubo, Masahito; Toriumi, Shin; Watanabe, Tetsuya; Yokoyama,
   Takaaki; Korendyke, Clarence M.; Warren, Harry P.; Tarbell, Ted; De
   Pontieu, Bart; Teriaca, Luca; Schühle, Udo H.; Solanki, Sami; Harra,
   Louise K.; Matthews, Sarah; Fludra, A.; Auchère, F.; Andretta, V.;
   Naletto, G.; Zhukov, A.
Bibcode: 2019SPIE11118E..07S
Altcode:
  Solar-C EUVST (EUV High-Throughput Spectroscopic Telescope) is a
  solar physics mission concept that was selected as a candidate for
  JAXA competitive M-class missions in July 2018. The onboard science
  instrument, EUVST, is an EUV spectrometer with slit-jaw imaging
  system that will simultaneously observe the solar atmosphere from the
  photosphere/chromosphere up to the corona with seamless temperature
  coverage, high spatial resolution, and high throughput for the first
  time. The mission is designed to provide a conclusive answer to the
  most fundamental questions in solar physics: how fundamental processes
  lead to the formation of the solar atmosphere and the solar wind, and
  how the solar atmosphere becomes unstable, releasing the energy that
  drives solar flares and eruptions. The entire instrument structure
  and the primary mirror assembly with scanning and tip-tilt fine
  pointing capability for the EUVST are being developed in Japan, with
  spectrograph and slit-jaw imaging hardware and science contributions
  from US and European countries. The mission will be launched and
  installed in a sun-synchronous polar orbit by a JAXA Epsilon vehicle in
  2025. ISAS/JAXA coordinates the conceptual study activities during the
  current mission definition phase in collaboration with NAOJ and other
  universities. The team is currently working towards the JAXA final
  down-selection expected at the end of 2019, with strong support from
  US and European colleagues. The paper provides an overall description
  of the mission concept, key technologies, and the latest status.

Title: Design of all-reflective space-borne 1-m aperture solar
    optical telescope
Authors: Suematsu, Y.; Hara, H.; Katsukawa, Y.; Kano, R.; Shimizu,
   T.; Ichimoto, K.
Bibcode: 2019SPIE11180E..0RS
Altcode:
  A 1-m aperture optical telescope is planned for a future Japanese solar
  mission. The telescope is designed to provide high spatial resolution
  data of solar lower atmosphere from the photosphere to the uppermost
  chromosphere with enhanced spectroscopic and spectro-polarimetric
  capabilities covering a wide wavelength region from UV to near IR where
  many useful spectral lines and continua exist for physical diagnosis of
  the solar magnetized atmosphere. We designed an allreflective telescope
  to fulfill the scientific and engineering requirements. From a thermal
  view point, a Gregorian telescope is the most suitable. To avoid
  chromatic aberration, a tri-aspheric-mirror collimator coupling to
  the Gregorian was designed to give a diffraction-limited performance
  over the FOV by allowing a field curvature. The field curvature can
  be compensated by an off-axis Ritchey Chretien reimaging optics at an
  entrance of focal plane instrument, which has an opposite sign in the
  field curvature to the Gregorian. We also briefly studied structural
  design of all-reflective 1-m aperture solar optical telescope for the
  space solar mission.

Title: Chromospheric polarimetry through multiline observations of
the 850 nm spectral region III: Chromospheric jets driven by twisted
    magnetic fields
Authors: Quintero Noda, C.; Iijima, H.; Katsukawa, Y.; Shimizu,
   T.; Carlsson, M.; de la Cruz Rodríguez, J.; Ruiz Cobo, B.; Orozco
   Suárez, D.; Oba, T.; Anan, T.; Kubo, M.; Kawabata, Y.; Ichimoto,
   K.; Suematsu, Y.
Bibcode: 2019MNRAS.486.4203Q
Altcode: 2019MNRAS.tmp.1081N; 2019arXiv190409151Q
  We investigate the diagnostic potential of the spectral lines at 850
  nm for understanding the magnetism of the lower atmosphere. For that
  purpose, we use a newly developed 3D simulation of a chromospheric
  jet to check the sensitivity of the spectral lines to this phenomenon
  as well as our ability to infer the atmospheric information through
  spectropolarimetric inversions of noisy synthetic data. We start
  comparing the benefits of inverting the entire spectrum at 850 nm versus
  only the Ca II 8542 Å spectral line. We found a better match of the
  input atmosphere for the former case, mainly at lower heights. However,
  the results at higher layers were not accurate. After several tests,
  we determined that we need to weight more the chromospheric lines
  than the photospheric ones in the computation of the goodness of the
  fit. The new inversion configuration allows us to obtain better fits and
  consequently more accurate physical parameters. Therefore, to extract
  the most from multiline inversions, a proper set of weights needs to
  be estimated. Besides that, we conclude again that the lines at 850
  nm, or a similar arrangement with Ca II 8542 Å plus Zeeman-sensitive
  photospheric lines, pose the best-observing configuration for examining
  the thermal and magnetic properties of the lower solar atmosphere.

Title: Synoptic Studies of the Sun as a Key to Understanding Stellar
    Astrospheres
Authors: Martinez Pillet, Valentin; Hill, Frank; Hammel, Heidi B.;
   de Wijn, Alfred G.; Gosain, Sanjay; Burkepile, Joan; Henney, Carl;
   McAteer, R. T. James; Bain, Hazel; Manchester, Ward; Lin, Haosheng;
   Roth, Markus; Ichimoto, Kiyoshi; Suematsu, Yoshinori
Bibcode: 2019BAAS...51c.110M
Altcode: 2019astro2020T.110M; 2019arXiv190306944M
  Ground-based solar observations provide key contextual data (i.e., the
  "big picture") to produce a complete description of the only astrosphere
  we can study in situ: our Sun's heliosphere. This white paper outlines
  the current paradigm for ground-based solar synoptic observations,
  and indicates those areas that will benefit from focused attention.

Title: Comparison of Scattering Polarization Signals Observed by
CLASP: Possible Indication of the Hanle Effect
Authors: Ishikawa, R.; Trujillo Bueno, J.; Uitenbroek, H.; Kubo, M.;
   Tsuneta, S.; Goto, M.; Kano, R.; Narukage, N.; Bando, T.; Katsukawa,
   Y.; Ishikawa, S.; Giono, G.; Suematsu, Y.; Hara, H.; Shimizu, T.;
   Sakao, T.; Winebarger, A.; Kobayashi, K.; Cirtain, J.; Champey, P.;
   Auchère, F.; Štěpán, J.; Belluzzi, L.; Asensio Ramos, A.; Manso
   Sainz, R.; De Pomtieu, B.; Ichimoto, K.; Carlsson, M.; Casini, R.
Bibcode: 2019ASPC..526..305I
Altcode:
  The Chromospheric Lyman-Alpha Spectro-Polarimeter (CLASP; Kano et
  al. 2012; Kobayashi et al. 2012; Kubo et al. 2014) observed, for the
  first time, the linear polarization produced by scattering processes
  in the hydrogen Lyman-α (121.57 nm) and Si III (120.56 nm) lines of
  the solar disk radiation. The complexity of the observed scattering
  polarization (i.e., conspicuous spatial variations in Q/I and U/I
  at spatial scales of 10″-20″ and the absence of center-to- limb
  variation at the Lyman-α center; see Kano et al. 2017) motivated us
  to search for possible hints of the operation of the Hanle effect by
  comparing: (a) the Lyman-α line center signal, for which the critical
  field strength (B<SUB>H</SUB>) for the onset of the Hanle effect is
  53 G, (b) the Lyman-α wing, which is insensitive to the Hanle effect,
  and (c) the Si III line, whose B<SUB>H</SUB> = 290 G. We focus on four
  regions with different total unsigned photospheric magnetic fluxes
  (estimated from SDO/HMI observations), and compare the corresponding
  U/I spatial variations in the Lyman-α wing, Lyman-α center, and Si III
  line. The U/I signal in the Lyman-α wing shows an antisymmetric spatial
  distribution, which is caused by the presence of a bright structure in
  all the selected regions, regardless of the total unsigned photospheric
  magnetic flux. In an internetwork region, the Lyman-α center shows an
  antisymmetric spatial variation across the selected bright structure,
  but it does not show it in other more magnetized regions. In the Si III
  line, the spatial variation of U/I deviates from the above-mentioned
  antisymmetric shape as the total unsigned photospheric magnetic flux
  increases. We argue that a plausible explanation of this differential
  behavior is the operation of the Hanle effect. <P />This work, presented
  in an oral contribution at this Workshop, has been published on The
  Astrophysical Journal (Ishikawa et al. 2017).

Title: Study of the polarization produced by the Zeeman effect in
    the solar Mg I b lines
Authors: Quintero Noda, C.; Uitenbroek, H.; Carlsson, M.; Orozco
   Suárez, D.; Katsukawa, Y.; Shimizu, T.; Ruiz Cobo, B.; Kubo, M.; Oba,
   T.; Kawabata, Y.; Hasegawa, T.; Ichimoto, K.; Anan, T.; Suematsu, Y.
Bibcode: 2018MNRAS.481.5675Q
Altcode: 2018arXiv181001067Q; 2018MNRAS.tmp.2566Q
  The next generation of solar observatories aim to understand the
  magnetism of the solar chromosphere. Therefore, it is crucial to
  understand the polarimetric signatures of chromospheric spectral
  lines. For this purpose, we here examine the suitability of the three
  Fraunhofer Mg I b<SUB>1</SUB>, b<SUB>2</SUB>, and b<SUB>4</SUB> lines
  at 5183.6, 5172.7, and 5167.3 Å, respectively. We start by describing
  a simplified atomic model of only six levels and three line transitions
  for computing the atomic populations of the 3p-4s (multiplet number
  2) levels involved in the Mg I b line transitions assuming non-local
  thermodynamic conditions and considering only the Zeeman effect using
  the field-free approximation. We test this simplified atom against
  more complex ones finding that, although there are differences in the
  computed profiles, they are small compared with the advantages provided
  by the simple atom in terms of speed and robustness. After comparing
  the three Mg I lines, we conclude that the most capable one is the
  b<SUB>2</SUB> line as b<SUB>1</SUB> forms at similar heights and always
  shows weaker polarization signals, while b<SUB>4</SUB> is severely
  blended with photospheric lines. We also compare Mg I b<SUB>2</SUB>
  with the K I D<SUB>1</SUB> and Ca II 8542 Å lines finding that the
  former is sensitive to the atmospheric parameters at heights that
  are in between those covered by the latter two lines. This makes Mg I
  b<SUB>2</SUB> an excellent candidate for future multiline observations
  that aim to seamlessly infer the thermal and magnetic properties of
  different features in the lower solar atmosphere.

Title: CLASP Constraints on the Magnetization and Geometrical
    Complexity of the Chromosphere-Corona Transition Region
Authors: Trujillo Bueno, J.; Štěpán, J.; Belluzzi, L.; Asensio
   Ramos, A.; Manso Sainz, R.; del Pino Alemán, T.; Casini, R.; Ishikawa,
   R.; Kano, R.; Winebarger, A.; Auchère, F.; Narukage, N.; Kobayashi,
   K.; Bando, T.; Katsukawa, Y.; Kubo, M.; Ishikawa, S.; Giono, G.; Hara,
   H.; Suematsu, Y.; Shimizu, T.; Sakao, T.; Tsuneta, S.; Ichimoto, K.;
   Cirtain, J.; Champey, P.; De Pontieu, B.; Carlsson, M.
Bibcode: 2018ApJ...866L..15T
Altcode: 2018arXiv180908865T
  The Chromospheric Lyman-Alpha Spectro-Polarimeter (CLASP) is a
  suborbital rocket experiment that on 2015 September 3 measured
  the linear polarization produced by scattering processes in the
  hydrogen Lyα line of the solar disk radiation. The line-center
  photons of this spectral line radiation mostly stem from the
  chromosphere-corona transition region (TR). These unprecedented
  spectropolarimetric observations revealed an interesting surprise,
  namely that there is practically no center-to-limb variation (CLV) in
  the Q/I line-center signals. Using an analytical model, we first show
  that the geometric complexity of the corrugated surface that delineates
  the TR has a crucial impact on the CLV of the Q/I and U/I line-center
  signals. Second, we introduce a statistical description of the solar
  atmosphere based on a 3D model derived from a state-of-the-art radiation
  magnetohydrodynamic simulation. Each realization of the statistical
  ensemble is a 3D model characterized by a given degree of magnetization
  and corrugation of the TR, and for each such realization we solve the
  full 3D radiative transfer problem taking into account the impact
  of the CLASP instrument degradation on the calculated polarization
  signals. Finally, we apply the statistical inference method presented
  in a previous paper to show that the TR of the 3D model that produces
  the best agreement with the CLASP observations has a relatively weak
  magnetic field and a relatively high degree of corrugation. We emphasize
  that a suitable way to validate or refute numerical models of the upper
  solar chromosphere is by confronting calculations and observations
  of the scattering polarization in ultraviolet lines sensitive to the
  Hanle effect.

Title: A Statistical Inference Method for Interpreting the CLASP
    Observations
Authors: Štěpán, J.; Trujillo Bueno, J.; Belluzzi, L.; Asensio
   Ramos, A.; Manso Sainz, R.; del Pino Alemán, T.; Casini, R.; Kano, R.;
   Winebarger, A.; Auchère, F.; Ishikawa, R.; Narukage, N.; Kobayashi,
   K.; Bando, T.; Katsukawa, Y.; Kubo, M.; Ishikawa, S.; Giono, G.; Hara,
   H.; Suematsu, Y.; Shimizu, T.; Sakao, T.; Tsuneta, S.; Ichimoto, K.;
   Cirtain, J.; Champey, P.; De Pontieu, B.; Carlsson, M.
Bibcode: 2018ApJ...865...48S
Altcode: 2018arXiv180802725S
  On 2015 September 3, the Chromospheric Lyman-Alpha SpectroPolarimeter
  (CLASP) successfully measured the linear polarization produced by
  scattering processes in the hydrogen Lyα line of the solar disk
  radiation, revealing conspicuous spatial variations in the Q/I and U/I
  signals. Via the Hanle effect, the line-center Q/I and U/I amplitudes
  encode information on the magnetic field of the chromosphere-corona
  transition region, but they are also sensitive to the three-dimensional
  structure of this corrugated interface region. With the help of a simple
  line-formation model, here we propose a statistical inference method
  for interpreting the Lyα line-center polarization observed by CLASP.

Title: Sunrise Chromospheric Infrared spectroPolarimeter (SCIP)
    for the SUNRISE balloon-borne solar observatory
Authors: Suematsu, Yoshinori; Katsukawa, Yukio; Hara, Hirohisa;
   Ichimoto, Kiyoshi; Shimizu, Toshifumi; Kubo, Masahito; Barthol,
   Peter; Riethmueller, Tino; Gandorfer, Achim; Feller, Alex; Orozco
   Suárez, David; Del Toro Iniesta, Jose Carlos; Kano, Ryouhei; Ishikawa,
   Shin-nosuke; Ishikawa, Ryohko; Tsuzuki, Toshihiro; Uraguchi, Fumihiro;
   Quintero Noda, Carlos; Tamura, Tomonori; Oba, Takayoshi; Kawabata,
   Yusuke; Nagata, Shinichi; Anan, Tetsu; Cobos Carrascosa, Juan Pedro;
   Lopez Jimenez, Antonio Carlos; Balaguer Jimenez, Maria; Solanki, Sami
Bibcode: 2018cosp...42E3285S
Altcode:
  The SUNRISE balloon-borne solar observatory carries a 1 m aperture
  optical telescope, and allows us to perform seeing-free continuous
  observations at visible-IR wavelengths from an altitude higher than
  35 km. In the past two flights, in 2009 and 2013, observations mainly
  focused on fine structures of photospheric magnetic fields. For the
  third flight planned for 2021, we are developing a new instrument
  for conducting spectro-polarimetry of spectral lines formed over a
  larger height range in the solar atmosphere from the photosphere to
  the chromosphere. Targets of the spectro-polarimetric observation
  are (1) to determine 3D magnetic structure from the photosphere to
  the chromosphere, (2) to trace MHD waves from the photosphere to the
  chromosphere, and (3) to reveal the mechanism driving chromospheric
  jets, by measuring height- and time-dependent velocities and magnetic
  fields. To achieve these goals, a spectro-polarimeter called SCIP
  (Sunrise Chromospheric Infrared spectroPolarimeter) is designed to
  observe near-infrared spectrum lines sensitive to solar magnetic
  fields. The spatial and spectral resolutions are 0.2 arcsec and
  200,000, respectively, while 0.03% polarimetric sensitivity is
  achieved within a 10 sec integration time. The optical system employs
  an Echelle grating and off-axis aspheric mirrors to observe the two
  wavelength ranges centered at 850 nm and 770 nm simultaneously by
  two cameras. Polarimetric measurements are performed using a rotating
  waveplate and polarization beam-splitters in front of the cameras. For
  detecting minute polarization signals with good precision, we carefully
  assess the temperature dependence of polarization optics, and make
  the opto-structural design that minimizes the thermal deformation
  of the spectrograph optics. Another key technique is to attain good
  (better than 30 msec) synchronization among the rotating phase of
  the waveplate, read-out timing of cameras, and step timing of a
  slit-scanning mirror. On-board accumulation and data processing are
  also critical because we cannot store all the raw data read-out from the
  cameras. We demonstrate that we can reduce the data down to almost 10%
  with loss-less image compression and without sacrificing polarimetric
  information in the data. The SCIP instrument is developed by internal
  collaboration among Japanese institutes including Japan Aerospace
  Exploration Agency (JAXA), the Spanish Sunrise consortium, and the
  German Max Planck Institute for Solar System Research (MPS) with a
  leadership of the National Astronomical Observatory of Japan (NAOJ).

Title: Solar Flare Observations with Integral Field Spectroscopy in
    H-alpha Spectra and SDO/AIA
Authors: Suematsu, Yoshinori
Bibcode: 2018cosp...42E3284S
Altcode:
  Integral field spectroscopy is a two dimensional spectroscopic
  technique, providing spectra simultaneously for each spatial direction
  of an extended two-dimensional field. Using the field integral
  spectroscopy made of microlenslet-array (30x30 lenslets) in H-alpha
  spectrum, GOES C- and M-class flares on 3 Nov 2011 were successfully
  observed with the 60 cm aperture Domeless Solar Telescope at Hida
  Observatory, Kyoto University. The data spatially sampled with 0.5
  arcsec over 10x10 arcsec FOV and 1 nm wavelength band centered H-alpha
  line demonstrated that simultaneous 2D spectroscopic observations
  over extended solar structures, at a high spatial resolution and
  temporal cadence, are important to track and understand the physics of
  transient phenomena happening in impulsive flare bright kernels. We
  made monochromatic images at given wavelengths in the H-alpha line
  and nearby continuum to co-align the data with X-ray, UV images and
  magnetograms from SDO/AIA and HMI. To reveal dynamical properties of
  the flare kernels, we carried out line profile analysis and derived
  2-D distribution of parameters such as line-of-sight velocity and line
  width. The results clearly show the rapid development of red asymmetry
  at the flare kernels, giving a large downward Doppler shifts of up to
  50 km/sec. The accompanied formation of coronal dynamic flaring loop
  structures seen in SDO X-ray images are consistent with a scenario
  of downward motion of compressed chromospheric flare kernels due do
  impulsive heat flow from the corona to the chromosphere and simultaneous
  evaporation of the chromospheric material into the corona.

Title: Science Objectives of the Solar-C_EUVST
Authors: Imada, Shinsuke; Suematsu, Yoshinori
Bibcode: 2018cosp...42E1542I
Altcode:
  Solar-C EUVST (EUV High-Throughput Spectroscopic Telescope) is
  designed to comprehensively understand the energy and mass transfer
  from the solar surface to the solar corona and interplanetary
  space, and to investigate the elementary processes that take place
  universally in cosmic plasmas. The proposed mission is a fundamental
  step for answering how the plasma universe is created and evolves,
  and how the Sun influences the Earth and other planets in our solar
  system. The two primary science objectives for Solar-C EUVST are : I)
  Understand how fundamental processes lead to the formation of the solar
  atmosphere and the solar wind, II) Understand how the solar atmosphere
  becomes unstable, releasing the energy that drives solar flares and
  eruptions. Solar-C EUVST will, A) seamlessly observe all the temperature
  regimes of the solar atmosphere from the chromosphere to the corona at
  the same time, B) resolve elemental structures of the solar atmosphere
  with high spatial resolution and cadence to track their evolution,
  and C) obtain spectroscopic information on the dynamics of elementary
  processes taking place in the solar atmosphere. In this talk, we will
  first discuss the science target of the Solar-C EUVST, and discuss the
  science topic associated flare in detail. Photospheric motions lead to
  the accumulation of free magnetic energy in the corona. This system
  eventually becomes unstable, releasing the energy through magnetic
  reconnection. This process of energy conversion heats the plasma to
  high temperatures and drives coronal mass ejections (CMEs). By measuring
  the properties of multi-temperature flaring plasma, Solar-C EUVST will
  investigate why the reconnection is fast despite the high magnetic
  Reynolds number. It will also monitor the temporal evolution of solar
  active regions and identify the triggering mechanism for the flare
  and eruption. Therefore two important science objectives are defined
  for the flare physics. The first objective is "Understand the Fast
  Magnetic Reconnection Process". Magnetic reconnection is one of the
  fundamental processes for converting magnetic energy into the thermal
  and kinetic energy of the plasma. This process occurs much faster
  than is predicted by classical theory. Solar-C EUVST will observe the
  dynamics of magnetic structures to understand the mechanisms that lead
  to fast magnetic reconnection in partially or fully ionized plasmas. The
  second objective is "Identify the Signatures of Global Energy Buildup
  and the Local Triggering of the Flare and Eruption". Understanding the
  accumulation and release of free magnetic energy in the corona is a
  fundamental problem. Solar-C EUVST will perform long-term monitoring
  of active regions to identify the signatures of energy buildup and
  high-resolution observations to understand the triggers of energy
  release.

Title: Current State of UV Spectro-Polarimetry and its Future
    Direction
Authors: Ishikawa, Ryohko; Sakao, Taro; Katsukawa, Yukio; Hara,
   Hirohisa; Ichimoto, Kiyoshi; Shimizu, Toshifumi; Kubo, Masahito;
   Auchere, Frederic; De Pontieu, Bart; Winebarger, Amy; Kobayashi,
   . Ken; Kano, Ryouhei; Narukage, Noriyuki; Trujillo Bueno, Javier;
   Song, Dong-uk; Manso Sainz, Rafael; Asensio Ramos, Andres; Leenaarts,
   Jorritt; Carlsson, Mats; Bando, Takamasa; Ishikawa, Shin-nosuke;
   Tsuneta, Saku; Belluzzi, Luca; Suematsu, Yoshinori; Giono, Gabriel;
   Yoshida, Masaki; Goto, Motoshi; Del Pino Aleman, Tanausu; Stepan,
   Jiri; Okamoto, Joten; Tsuzuki, Toshihiro; Uraguchi, Fumihiro; Champey,
   Patrick; Alsina Ballester, Ernest; Casini, Roberto; McKenzie, David;
   Rachmeler, Laurel; Bethge, Christian
Bibcode: 2018cosp...42E1564I
Altcode:
  To obtain quantitative information on the magnetic field in low beta
  regions (i.e., upper chromosphere and above) has been increasingly
  important to understand the energetic phenomena of the outer
  solar atmosphere such as flare, coronal heating, and the solar wind
  acceleration. In the UV range, there are abundant spectral lines that
  originate in the upper chromosphere and transition region. However,
  the Zeeman effect in these spectral lines does not give rise to easily
  measurable polarization signals because of the weak magnetic field
  strength and the larger Doppler broadening compared with the Zeeman
  effect. Instead, the Hanle effect in UV lines is expected to be a
  suitable diagnostic tool of the magnetic field in the upper atmospheric
  layers. To investigate the validity of UV spectro-polarimetry and
  the Hanle effect, the Chromospheric Lyman-Alpha Spectro-Polarimeter
  (CLASP), which is a NASA sounding- rocket experiment, was launched at
  White Sands in US on September 3, 2015. During its 5 minutes ballistic
  flight, it successfully performed spectro-polarimetric observations
  of the hydrogen Lyman-alpha line (121.57 nm) with an unprecedentedly
  high polarization sensitivity of 0.1% in this wavelength range. CLASP
  observed the linear polarization produced by scattering process in VUV
  lines for the first time and detected the polarization signals which
  indicate the operation of the Hanle effect. Following the success
  of CLASP, we are confident that UV spectro-polarimetry is the way
  to proceed, and we are planning the second flight of CLASP (CLASP2:
  Chromospheric LAyer SpectroPolarimeter 2). For this second flight we
  will carry out spectro-polarimetry in the Mg II h and k lines around
  280 nm, with minimum modifications of the CLASP1 instrument. The linear
  polarization in the Mg II k line is induced by scattering processes and
  the Hanle effect, being sensitive to magnetic field strengths of 5 to 50
  G. In addition, the circular polarizations in the Mg II h and k lines
  induced by the Zeeman effect can be measurable in at least plage and
  active regions. The combination of the Hanle and Zeeman effects could
  help us to more reliably infer the magnetic fields of the upper solar
  chromosphere. CLASP2 was selected for flight and is being developed for
  launch in the spring of 2019.Based on these sounding rocket experiments
  (CLASP1 and 2), we aim at establishing the strategy and refining the
  instrument concept for future space missions to explore the enigmatic
  atmospheric layers via UV spectro-polarimetry.

Title: Wavefront error measurements and alignment of CLASP2 telescope
    with a dual-band pass cold mirror coated primary mirror
Authors: Yoshida, Masaki; Song, Donguk; Ishikawa, Ryoko; Kano, Ryouhei;
   Katsukawa, Yukio; Suematsu, Yoshinori; Narukage, Noriyuki; Kubo,
   Masahito; Shinoda, Kazuya; Okamoto, Takenori J.; McKenzie, David E.;
   Rachmeler, Laurel A.; Auchère, Frédéric; Trujillo Bueno, Javier
Bibcode: 2018SPIE10699E..30Y
Altcode:
  "Chromospheric LAyer Spectro-Polarimeter (CLASP2)" is the next sounding
  rocket experiment of the "Chromospheric Lyman-Alpha Spectro-Polarimeter
  (CLASP)" that succeeded in observing for the first time the linear
  polarization spectra in the hydrogen Lyman-α line (121.6 nm) and is
  scheduled to be launched in 2019. In CLASP2, we will carry out full
  Stokes-vector spectropolarimetric observations in the Mg ii h and k
  lines near 280 nm with the spectro-polarimeter (SP), while imaging
  observations in the Lyman-α line will be conducted with the slitjaw
  optics (SJ). For the wavelength selection of CLASP2, the primary
  mirror of the telescope uses a new dual-band pass cold mirror coating
  targeting both at 121.6 nm and 280 nm. Therefore, we have to perform
  again the alignment of the telescope after the installation of the
  recoated primary mirror. Before unmounting the primary mirror from
  the telescope structure, we measured the wave-front error (WFE) of the
  telescope. The measured WFE map was consistent with what we had before
  the CLASP flight, clearly indicating that the telescope alignment has
  been maintained even after the flight. After the re-coated primary
  mirror was installed the WFE was measured, and coma aberration was
  found to be larger. Finally, the secondary mirror shim adjustments
  were carried out based on the WFE measurements. In CLASP2 telescope,
  we improved a fitting method of WFE map (applying 8th terms circular
  Zernike polynomial fitting instead of 37th terms circular Zernike
  fitting) and the improved method enables to achieve better performance
  than CLASP telescope. Indeed, WFE map obtained after the final shim
  adjustment indicated that the required specification (&lt; 5.5 μm
  RMS spot radius) that is more stringent than CLASP telescope was met.

Title: Solar polarimetry in the K I D<SUB>2</SUB> line : A novel
    possibility for a stratospheric balloon
Authors: Quintero Noda, C.; Villanueva, G. L.; Katsukawa, Y.; Solanki,
   S. K.; Orozco Suárez, D.; Ruiz Cobo, B.; Shimizu, T.; Oba, T.; Kubo,
   M.; Anan, T.; Ichimoto, K.; Suematsu, Y.
Bibcode: 2018A&A...610A..79Q
Altcode: 2018arXiv180101655Q
  Of the two solar lines, K I D<SUB>1</SUB> and D<SUB>2</SUB>, almost
  all attention so far has been devoted to the D<SUB>1</SUB> line, as
  D<SUB>2</SUB> is severely affected by an O<SUB>2</SUB> atmospheric
  band. This, however, makes the latter appealing for balloon and space
  observations from above (most of) the Earth's atmosphere. We estimate
  the residual effect of the O<SUB>2</SUB> band on the K I D<SUB>2</SUB>
  line at altitudes typical for stratospheric balloons. Our aim is to
  study the feasibility of observing the 770 nm window. Specifically,
  this paper serves as a preparation for the third flight of the Sunrise
  balloon-borne observatory. The results indicate that the absorption
  by O<SUB>2</SUB> is still present, albeit much weaker, at the expected
  balloon altitude. We applied the obtained O<SUB>2</SUB> transmittance
  to K I D<SUB>2</SUB> synthetic polarimetric spectra and found that in
  the absence of line-of-sight motions, the residual O<SUB>2</SUB> has
  a negligible effect on the K I D<SUB>2</SUB> line. On the other hand,
  for Doppler-shifted K I D<SUB>2</SUB> data, the residual O<SUB>2</SUB>
  might alter the shape of the Stokes profiles. However, the residual
  O<SUB>2</SUB> absorption is sufficiently weak at stratospheric levels
  that it can be divided out if appropriate measurements are made,
  something that is impossible at ground level. Therefore, for the
  first time with Sunrise III, we will be able to perform polarimetric
  observations of the K I D<SUB>2</SUB> line and, consequently, we will
  have improved access to the thermodynamics and magnetic properties of
  the upper photosphere from observations of the K I lines.

Title: Ten-Year Results of Solar Optical Telescope (SOT) Onboard
    Hinode
Authors: Suematsu, Yoshinori
Bibcode: 2018ASSL..449...27S
Altcode:
  No abstract at ADS

Title: Development of compact integral field unit for spaceborne
    solar spectro-polarimeter
Authors: Suematsu, Y.; Koyama, M.; Sukegawa, T.; Enokida, Y.; Saito,
   K.; Okura, Y.; Nakayasu, T.; Ozaki, S.; Tsuneta, S.
Bibcode: 2017SPIE10563E..4MS
Altcode:
  A 1.5-m class aperture Solar Ultra-violet Visible and IR telescope
  (SUVIT) and its instruments for the Japanese next space solar mission
  SOLAR-C [1] are under study to obtain critical physical parameters in
  the lower solar atmosphere. For the precise magnetic field measurements
  covering field-of-view of 3 arcmin x3 acmin, a full stokes polarimetry
  at three magnetic sensitive lines in wavelength range of 525 nm
  to 1083 nm with a four-slit spectrograph of two dinesional image
  scanning mechanism is proposed: one is a true slit and the other
  three are pseudo-slits from integral field unit (IFU). To suit this
  configuration, besides a fiber bundle IFU, a compact mirror slicer IFU
  is designed and being developed. Integral field spectroscopy (IFS),
  which is realized with IFU, is a two dimensional spectroscopy, providing
  spectra simultaneously for each spatial direction of an extended
  two-dimensional field. The scientific advantages of the IFS for studies
  of localized and transient solar surface phenomena are obvious. There
  are in general three methods [2][3] to realize the IFS depending on
  image slicing devices such as a micro-lenslet array, an optical fiber
  bundle and a narrow rectangular image slicer array. So far, there exist
  many applications of the IFS for ground-based astronomical observations
  [4]. Regarding solar instrumentations, the IFS of micro-lenslet array
  was done by Suematsu et al. [5], the IFS of densely packed rectangular
  fiber bundle with thin clads was realized [6] and being developed for
  4-m aperture solar telescope DKIST by Lin [7] and being considered for
  space solar telescope SOLAR-C by Katsukawa et al. [8], and the IFS with
  mirror slicer array was presented by Ren et al. [9] and under study
  for up-coming large-aperture solar telescope in Europe by Calcines
  et al. [10] From the view point of a high efficiency spectroscopy,
  a wide wavelength coverage, a precision spectropolarimetry and space
  application, the image slicer consisting of all reflective optics is the
  best option among the three. However, the image slicers are presently
  limited either by their risk in the case of classical glass polishing
  techniques (see Vivès et al. [11] for recent development) or by their
  optical performances when constituted by metallic mirrors. For space
  instruments, small sized units are much advantageous and demands that
  width of each slicer mirror is as narrow as an optimal slit width (&lt;
  100 micron) of spectrograph which is usually hard to manufacture with
  glass polishing techniques. On the other hand, Canon is developing
  a novel technique for such as high performance gratings which can be
  applicable for manufacturing high optical performance metallic mirrors
  of small dimensions. For the space-borne spectrograph of SUVIT to be
  aboard SOLAR-C, we designed the IFS made of a micro image slicer of 45
  arrayed 30-micron-thick metal mirrors and a pseudo-pupil metal mirror
  array re-formatting three pseudo-slits; the design is feasible for
  optical configuration sharing a spectrograph with a conventional real
  slit. According to the optical deign, Canon manufactured a prototype
  IFU for evaluation, demonstrating high performances of micro image
  slicer and pupil mirrors; enough small micro roughness for visible light
  spectrographs, sharp edges for efficient image slices, surface figure
  for high image quality, etc. In the following, we describe the optical
  design of IFU feasible for space-borne spectrograph, manufacturing
  method to attain high optical performance of metal mirrors developed
  by Canon, and resulted performance of prototype IFU in detail.

Title: Instrument design and on-orbit performance of the solar
    optical telescope aboard hinode (Solar-B)
Authors: Suematsu, Yoshinori; Ichimoto, Kiyoshi; Katsukawa, Yukio;
   Tsuneta, Saku; Shimizu, Toshifumi
Bibcode: 2017SPIE10566E..2ZS
Altcode:
  The Solar Optical Telescope (SOT) aboard Solar-B satellite (Hinode)
  is designed to perform high-precision photometric and polarimetric
  observations of the solar lower atmosphere in visible light spectra
  (388-668 nm) with a spatial resolution of 0.2 to 0.3 arcsec. The
  SOT consists of two components; the optical telescope assembly (OTA)
  consisting of a 50-cm aperture Gregorian telescope with a collimating
  lens unit and an active tip-tilt mirror for an image-stabilization and
  an accompanying focal plane package (FPP) housing two filtergraphs and a
  spectro-polarimeter. Since its first-light observation on 25 Oct. 2006,
  the image-stabilization system has been working with performance
  better than 0.01 arcsec rms and the SOT has been continuously
  providing unprecedented solar data of high spatial resolution. Since
  the opto-mechanical and -thermal performance of the OTA is crucial
  to attain unprecedented high-quality solar observations, we here
  describe in detail the instrument design and on-orbit diffraction-limit
  performance of the OTA, the largest state-of-the-art solar telescope
  yet flown in space.

Title: Instrument design of 1.5-m aperture solar optical telescope
    for the Solar-C Mission
Authors: Suematsu, Yoshinori; Katsukawa, Yukio; Shimizu, Toshifumi;
   Ichimoto, Kiyoshi
Bibcode: 2017SPIE10564E..0TS
Altcode:
  A 1.5 m aperture optical telescope is planned for the next Japanese
  solar mission SOLAR-C as one of major three observing instruments. The
  optical telescope is designed to provide high-angular-resolution
  investigation of lower atmosphere from the photosphere to the uppermost
  chromosphere with enhanced spectroscopic and spectropolarimetric
  capability covering a wide wavelength region from 280 nm to 1100
  nm. The opto-mechanical and -thermal performance of the telescope is
  crucial to attain high-quality solar observations and we present a
  study of optical and structural design of the large aperture space
  solar telescope, together with conceptual design of its accompanying
  focal plane instruments: wide-band and narrow-band filtergraphs and
  a spectro-polarimeter for high spatial and temporal observations in
  the solar photospheric and chromospheric lines useful for sounding
  physical condition of dynamical phenomena.

Title: Chromospheric polarimetry through multiline observations of
    the 850-nm spectral region - II. A magnetic flux tube scenario
Authors: Quintero Noda, C.; Kato, Y.; Katsukawa, Y.; Oba, T.; de la
   Cruz Rodríguez, J.; Carlsson, M.; Shimizu, T.; Orozco Suárez, D.;
   Ruiz Cobo, B.; Kubo, M.; Anan, T.; Ichimoto, K.; Suematsu, Y.
Bibcode: 2017MNRAS.472..727Q
Altcode: 2017arXiv170801333Q
  In this publication, we continue the work started in Quintero Noda et
  al., examining this time a numerical simulation of a magnetic flux
  tube concentration. Our goal is to study if the physical phenomena
  that take place in it, in particular, the magnetic pumping, leaves
  a specific imprint on the examined spectral lines. We find that the
  profiles from the interior of the flux tube are periodically doppler
  shifted following an oscillation pattern that is also reflected in
  the amplitude of the circular polarization signals. In addition, we
  analyse the properties of the Stokes profiles at the edges of the flux
  tube discovering the presence of linear polarization signals for the Ca
  II lines, although they are weak with an amplitude around 0.5 per cent
  of the continuum intensity. Finally, we compute the response functions
  to perturbations in the longitudinal field, and we estimate the field
  strength using the weak-field approximation. Our results indicate
  that the height of formation of the spectral lines changes during the
  magnetic pumping process, which makes the interpretation of the inferred
  magnetic field strength and its evolution more difficult. These results
  complement those from previous works, demonstrating the capabilities and
  limitations of the 850-nm spectrum for chromospheric Zeeman polarimetry
  in a very dynamic and complex atmosphere.

Title: Optical and thermal design of 1.5-m aperture solar UV visible
    and IR observing telescope for Solar-C mission
Authors: Suematsu, Y.; Katsukawa, Y.; Shimizu, T.; Ichimoto, K.;
   Horiuchi, T.; Matsumoto, Y.; Takeyama, N.
Bibcode: 2017SPIE10565E..0RS
Altcode:
  The next Japanese solar mission, SOLAR-C, which has been envisaged
  after successful science operation of Hinode (SOLAR-B) mission, is
  perusing two plans: plan-A and plan-B, and under extensive study from
  science objectives as well as engineering point of view. The plan-A
  aims at performing out-of-ecliptic observations for investigating, with
  helioseismic approach, internal structure and dynamo mechanisms of the
  Sun. It also explores polar regions where fast solar wind is believed
  to originate. A baseline orbit for plan-A is a circular orbit of 1 AU
  distance from the Sun with its inclination at around or greater than
  40 degrees. The plan-B aims to study small-scale plasma processes and
  structures in the solar atmosphere which attract researchers' growing
  interest, followed by many Hinode discoveries [1], for understanding
  fully dynamism and magnetic nature of the atmosphere. With plan-B,
  high-angular-resolution investigation of the entire solar atmosphere
  (from the photosphere to the corona, including their interface layers,
  i.e., chromosphere and transition region) is to be performed with
  enhanced spectroscopic and spectro-polarimetric capability as compared
  with Hinode, together with enhanced sensitivity towards ultra-violet
  wavelengths. The orbit of plan-B is either a solar synchronous polar
  orbit of altitude around 600 km or a geosynchronous orbit to ensure
  continuous solar observations. After the decision of any one of the
  two plans, the SOLAR-C will be proposed for launch in mid-2010s. In
  this paper, we will present a basic design of one of major planned
  instrumental payload for the plan-B: the Solar Ultra-violet Visible
  and near IR observing Telescope (hereafter referred to as SUVIT). The
  basic concept in designing the SUVIT is to utilize as much as possible
  a heritage of successful telescope of the Solar Optical Telescope
  (SOT) aboard Hinode [2]. Major differences of SUVIT from SOT are
  the three times larger aperture of 1.5 m, which enables to collect
  one order of magnitude more photons than SOT, relatively shorter
  telescope length of 2.8 m to accommodate a launcher's nosecone size
  for possible dual-satellite-launch configuration, and much wider
  observing wavelength from UV (down to 250 nm) through near IR (up
  to 1100 nm). The large aperture is essentially important to attain
  scientific goals of the plan-B, especially for accurate diagnostics of
  the dynamic solar chromosphere as revealed by Hinode, although this
  make it difficult to design the telescope because of ten times more
  solar heat load introduced into the telescope. The SUVIT consists of
  two optically separable components; the telescope assembly (TA) and
  an accompanying focal plane package equipped with filtergraphs and
  spectrographs. Opto-mechanical and -thermal performance of the TA is
  crucial to attain high-quality solar observations and here we present
  a status of feasible study in its optical and thermal designing for
  diffraction-limited performance at visible wavelength in a reasonably
  wide field of view.

Title: Solar polarimetry through the K I lines at 770 nm
Authors: Quintero Noda, C.; Uitenbroek, H.; Katsukawa, Y.; Shimizu,
   T.; Oba, T.; Carlsson, M.; Orozco Suárez, D.; Ruiz Cobo, B.; Kubo,
   M.; Anan, T.; Ichimoto, K.; Suematsu, Y.
Bibcode: 2017MNRAS.470.1453Q
Altcode: 2017arXiv170510002Q
  We characterize the K I D<SUB>1</SUB> &amp; D<SUB>2</SUB> lines in
  order to determine whether they could complement the 850 nm window,
  containing the Ca II infrared triplet lines and several Zeeman sensitive
  photospheric lines, that was studied previously. We investigate the
  effect of partial redistribution on the intensity profiles, their
  sensitivity to changes in different atmospheric parameters, and
  the spatial distribution of Zeeman polarization signals employing a
  realistic magnetohydrodynamic simulation. The results show that these
  lines form in the upper photosphere at around 500 km, and that they
  are sensitive to the line-of-sight velocity and magnetic field strength
  at heights where neither the photospheric lines nor the Ca II infrared
  lines are. However, at the same time, we found that their sensitivity
  to the temperature essentially comes from the photosphere. Then, we
  conclude that the K I lines provide a complement to the lines in the
  850 nm window for the determination of atmospheric parameters in the
  upper photosphere, especially for the line-of-sight velocity and the
  magnetic field.

Title: Compact integral field unit for optical telescope of the
    Solar-C mission
Authors: Suematsu, Y.; Saito, K.; Koyama, M.; Koyama, M.; Enokida,
   Y.; Okura, Y.; Nakayasu, T.; Sukegawa, T.
Bibcode: 2017SPIE10562E..0SS
Altcode:
  A Japan-led international solar mission "SOLAR-C" is being proposed
  for mid-2020s launch.

Title: Indication of the Hanle Effect by Comparing the Scattering
    Polarization Observed by CLASP in the Lyα and Si III 120.65 nm Lines
Authors: Ishikawa, R.; Trujillo Bueno, J.; Uitenbroek, H.; Kubo, M.;
   Tsuneta, S.; Goto, M.; Kano, R.; Narukage, N.; Bando, T.; Katsukawa,
   Y.; Ishikawa, S.; Giono, G.; Suematsu, Y.; Hara, H.; Shimizu, T.;
   Sakao, T.; Winebarger, A.; Kobayashi, K.; Cirtain, J.; Champey, P.;
   Auchère, F.; Štěpán, J.; Belluzzi, L.; Asensio Ramos, A.; Manso
   Sainz, R.; De Pontieu, B.; Ichimoto, K.; Carlsson, M.; Casini, R.
Bibcode: 2017ApJ...841...31I
Altcode:
  The Chromospheric Lyman-Alpha Spectro-Polarimeter is a sounding
  rocket experiment that has provided the first successful measurement
  of the linear polarization produced by scattering processes in
  the hydrogen Lyα line (121.57 nm) radiation of the solar disk. In
  this paper, we report that the Si III line at 120.65 nm also shows
  scattering polarization and we compare the scattering polarization
  signals observed in the Lyα and Si III lines in order to search for
  observational signatures of the Hanle effect. We focus on four selected
  bright structures and investigate how the U/I spatial variations vary
  between the Lyα wing, the Lyα core, and the Si III line as a function
  of the total unsigned photospheric magnetic flux estimated from Solar
  Dynamics Observatory/Helioseismic and Magnetic Imager observations. In
  an internetwork region, the Lyα core shows an antisymmetric spatial
  variation across the selected bright structure, but it does not show
  it in other more magnetized regions. In the Si III line, the spatial
  variation of U/I deviates from the above-mentioned antisymmetric
  shape as the total unsigned photospheric magnetic flux increases. A
  plausible explanation of this difference is the operation of the Hanle
  effect. We argue that diagnostic techniques based on the scattering
  polarization observed simultaneously in two spectral lines with very
  different sensitivities to the Hanle effect, like Lyα and Si III,
  are of great potential interest for exploring the magnetism of the
  upper solar chromosphere and transition region.

Title: Polarization Calibration of the Chromospheric Lyman-Alpha
    SpectroPolarimeter for a 0.1% Polarization Sensitivity in the VUV
Range. Part II: In-Flight Calibration
Authors: Giono, G.; Ishikawa, R.; Narukage, N.; Kano, R.; Katsukawa,
   Y.; Kubo, M.; Ishikawa, S.; Bando, T.; Hara, H.; Suematsu, Y.;
   Winebarger, A.; Kobayashi, K.; Auchère, F.; Trujillo Bueno, J.;
   Tsuneta, S.; Shimizu, T.; Sakao, T.; Cirtain, J.; Champey, P.; Asensio
   Ramos, A.; Štěpán, J.; Belluzzi, L.; Manso Sainz, R.; De Pontieu,
   B.; Ichimoto, K.; Carlsson, M.; Casini, R.; Goto, M.
Bibcode: 2017SoPh..292...57G
Altcode:
  The Chromospheric Lyman-Alpha SpectroPolarimeter is a sounding
  rocket instrument designed to measure for the first time the linear
  polarization of the hydrogen Lyman-α line (121.6 nm). The instrument
  was successfully launched on 3 September 2015 and observations were
  conducted at the solar disc center and close to the limb during the
  five-minutes flight. In this article, the disc center observations are
  used to provide an in-flight calibration of the instrument spurious
  polarization. The derived in-flight spurious polarization is consistent
  with the spurious polarization levels determined during the pre-flight
  calibration and a statistical analysis of the polarization fluctuations
  from solar origin is conducted to ensure a 0.014% precision on the
  spurious polarization. The combination of the pre-flight and the
  in-flight polarization calibrations provides a complete picture of
  the instrument response matrix, and a proper error transfer method
  is used to confirm the achieved polarization accuracy. As a result,
  the unprecedented 0.1% polarization accuracy of the instrument in the
  vacuum ultraviolet is ensured by the polarization calibration.

Title: Discovery of Scattering Polarization in the Hydrogen Lyα
    Line of the Solar Disk Radiation
Authors: Kano, R.; Trujillo Bueno, J.; Winebarger, A.; Auchère, F.;
   Narukage, N.; Ishikawa, R.; Kobayashi, K.; Bando, T.; Katsukawa, Y.;
   Kubo, M.; Ishikawa, S.; Giono, G.; Hara, H.; Suematsu, Y.; Shimizu,
   T.; Sakao, T.; Tsuneta, S.; Ichimoto, K.; Goto, M.; Belluzzi, L.;
   Štěpán, J.; Asensio Ramos, A.; Manso Sainz, R.; Champey, P.;
   Cirtain, J.; De Pontieu, B.; Casini, R.; Carlsson, M.
Bibcode: 2017ApJ...839L..10K
Altcode: 2017arXiv170403228K
  There is a thin transition region (TR) in the solar atmosphere where
  the temperature rises from 10,000 K in the chromosphere to millions
  of degrees in the corona. Little is known about the mechanisms that
  dominate this enigmatic region other than the magnetic field plays a
  key role. The magnetism of the TR can only be detected by polarimetric
  measurements of a few ultraviolet (UV) spectral lines, the Lyα line
  of neutral hydrogen at 121.6 nm (the strongest line of the solar UV
  spectrum) being of particular interest given its sensitivity to the
  Hanle effect (the magnetic-field-induced modification of the scattering
  line polarization). We report the discovery of linear polarization
  produced by scattering processes in the Lyα line, obtained with
  the Chromospheric Lyman-Alpha Spectro-Polarimeter (CLASP) rocket
  experiment. The Stokes profiles observed by CLASP in quiet regions of
  the solar disk show that the Q/I and U/I linear polarization signals are
  of the order of 0.1% in the line core and up to a few percent in the
  nearby wings, and that both have conspicuous spatial variations with
  scales of ∼10 arcsec. These observations help constrain theoretical
  models of the chromosphere-corona TR and extrapolations of the
  magnetic field from photospheric magnetograms. In fact, the observed
  spatial variation from disk to limb of polarization at the line core
  and wings already challenge the predictions from three-dimensional
  magnetohydrodynamical models of the upper solar chromosphere.

Title: Chromospheric polarimetry through multiline observations of
    the 850-nm spectral region
Authors: Quintero Noda, C.; Shimizu, T.; Katsukawa, Y.; de la Cruz
   Rodríguez, J.; Carlsson, M.; Anan, T.; Oba, T.; Ichimoto, K.;
   Suematsu, Y.
Bibcode: 2017MNRAS.464.4534Q
Altcode: 2016arXiv161006651Q
  Future solar missions and ground-based telescopes aim to understand the
  magnetism of the solar chromosphere. We performed a supporting study in
  Quintero Noda et al. focused on the infrared Ca II 8542 Å line and we
  concluded that it is one of the best candidates because it is sensitive
  to a large range of atmospheric heights, from the photosphere to the
  middle chromosphere. However, we believe that it is worth trying to
  improve the results produced by this line observing additional spectral
  lines. In that regard, we examined the neighbourhood solar spectrum
  looking for spectral lines which could increase the sensitivity to
  the atmospheric parameters. Interestingly, we discovered several
  photospheric lines which greatly improve the photospheric sensitivity
  to the magnetic field vector. Moreover, they are located close to a
  second chromospheric line which also belongs to the Ca II infrared
  triplet, I.e. the Ca II 8498 Å line, and enhances the sensitivity to
  the atmospheric parameters at chromospheric layers. We conclude that the
  lines in the vicinity of the Ca II 8542 Å line not only increase its
  sensitivity to the atmospheric parameters at all layers, but also they
  constitute an excellent spectral window for chromospheric polarimetry.

Title: Pre-eruption Oscillations in Thin and Long Features in a
    Quiescent Filament
Authors: Joshi, Anand D.; Hanaoka, Yoichiro; Suematsu, Yoshinori;
   Morita, Satoshi; Yurchyshyn, Vasyl; Cho, Kyung-Suk
Bibcode: 2016ApJ...833..243J
Altcode: 2016arXiv161204917J
  We investigate the eruption of a quiescent filament located close to
  an active region. Large-scale activation was observed in only half of
  the filament in the form of pre-eruption oscillations. Consequently
  only this half erupted nearly 30 hr after the oscillations
  commenced. Time-slice diagrams of 171 Å images from the Atmospheric
  Imaging Assembly were used to study the oscillations. These were
  observed in several thin and long features connecting the filament
  spine to the chromosphere below. This study traces the origin of
  such features and proposes their possible interpretation. Small-scale
  magnetic flux cancellation accompanied by a brightening was observed
  at the footpoint of the features shortly before their appearance, in
  images recorded by the Helioseismic and Magnetic Imager. A slow rise of
  the filament was detected in addition to the oscillations, indicating
  a gradual loss of equilibrium. Our analysis indicates that a change in
  magnetic field connectivity between two neighbouring active regions
  and the quiescent filament resulted in a weakening of the overlying
  arcade of the filament, leading to its eruption. It is also suggested
  that the oscillating features are filament barbs, and the oscillations
  are a manifestation during the pre-eruption phase of the filaments.

Title: Polarization Calibration of the Chromospheric Lyman-Alpha
    SpectroPolarimeter for a 0.1 % Polarization Sensitivity in the VUV
Range. Part I: Pre-flight Calibration
Authors: Giono, G.; Ishikawa, R.; Narukage, N.; Kano, R.; Katsukawa,
   Y.; Kubo, M.; Ishikawa, S.; Bando, T.; Hara, H.; Suematsu, Y.;
   Winebarger, A.; Kobayashi, K.; Auchère, F.; Trujillo Bueno, J.
Bibcode: 2016SoPh..291.3831G
Altcode: 2016SoPh..tmp..177G
  The Chromospheric Lyman-Alpha SpectroPolarimeter (CLASP) is a sounding
  rocket experiment designed to measure for the first time the linear
  polarization of the hydrogen Lyman-α line (121.6 nm) and requires
  a 0.1 % polarization sensitivity, which is unprecedented for a
  spectropolarimeter in the vacuum UV (VUV) spectral range.

Title: Discovery of Ubiquitous Fast-Propagating Intensity Disturbances
    by the Chromospheric Lyman Alpha Spectropolarimeter (CLASP)
Authors: Kubo, M.; Katsukawa, Y.; Suematsu, Y.; Kano, R.; Bando,
   T.; Narukage, N.; Ishikawa, R.; Hara, H.; Giono, G.; Tsuneta, S.;
   Ishikawa, S.; Shimizu, T.; Sakao, T.; Winebarger, A.; Kobayashi, K.;
   Cirtain, J.; Champey, P.; Auchère, F.; Trujillo Bueno, J.; Asensio
   Ramos, A.; Štěpán, J.; Belluzzi, L.; Manso Sainz, R.; De Pontieu,
   B.; Ichimoto, K.; Carlsson, M.; Casini, R.; Goto, M.
Bibcode: 2016ApJ...832..141K
Altcode:
  High-cadence observations by the slit-jaw (SJ) optics system of the
  sounding rocket experiment known as the Chromospheric Lyman Alpha
  Spectropolarimeter (CLASP) reveal ubiquitous intensity disturbances
  that recurrently propagate in either the chromosphere or the transition
  region or both at a speed much higher than the speed of sound. The
  CLASP/SJ instrument provides a time series of two-dimensional images
  taken with broadband filters centered on the Lyα line at a 0.6 s
  cadence. The multiple fast-propagating intensity disturbances appear in
  the quiet Sun and in an active region, and they are clearly detected in
  at least 20 areas in a field of view of 527″ × 527″ during the 5
  minute observing time. The apparent speeds of the intensity disturbances
  range from 150 to 350 km s<SUP>-1</SUP>, and they are comparable
  to the local Alfvén speed in the transition region. The intensity
  disturbances tend to propagate along bright elongated structures away
  from areas with strong photospheric magnetic fields. This suggests
  that the observed fast-propagating intensity disturbances are related
  to the magnetic canopy structures. The maximum distance traveled by
  the intensity disturbances is about 10″, and the widths are a few
  arcseconds, which are almost determined by a pixel size of 1.″03. The
  timescale of each intensity pulse is shorter than 30 s. One possible
  explanation for the fast-propagating intensity disturbances observed
  by CLASP is magnetohydrodynamic fast-mode waves.

Title: Analysis of a spatially deconvolved solar pore
Authors: Quintero Noda, C.; Shimizu, T.; Ruiz Cobo, B.; Suematsu,
   Y.; Katsukawa, Y.; Ichimoto, K.
Bibcode: 2016MNRAS.460.1476Q
Altcode: 2016arXiv160501796Q; 2016MNRAS.tmp..847Q
  Solar pores are active regions with large magnetic field strengths
  and apparent simple magnetic configurations. Their properties
  resemble the ones found for the sunspot umbra although pores do
  not show penumbra. Therefore, solar pores present themselves as an
  intriguing phenomenon that is not completely understood. We examine
  in this work a solar pore observed with Hinode/SP using two state
  of the art techniques. The first one is the spatial deconvolution
  of the spectropolarimetric data that allows removing the stray
  light contamination induced by the spatial point spread function
  of the telescope. The second one is the inversion of the Stokes
  profiles assuming local thermodynamic equilibrium that let us to
  infer the atmospheric physical parameters. After applying these
  techniques, we found that the spatial deconvolution method does not
  introduce artefacts, even at the edges of the magnetic structure,
  where large horizontal gradients are detected on the atmospheric
  parameters. Moreover, we also describe the physical properties of
  the magnetic structure at different heights finding that, in the
  inner part of the solar pore, the temperature is lower than outside,
  the magnetic field strength is larger than 2 kG and unipolar, and
  the line-of-sight velocity is almost null. At neighbouring pixels,
  we found low magnetic field strengths of same polarity and strong
  downward motions that only occur at the low photosphere, below the
  continuum optical depth log τ = -1. Finally, we studied the spatial
  relation between different atmospheric parameters at different heights
  corroborating the physical properties described before.

Title: Optical alignment of the Chromospheric Lyman-Alpha
    Spectro-Polarimeter using sophisticated methods to minimize activities
    under vacuum
Authors: Giono, G.; Katsukawa, Y.; Ishikawa, R.; Narukage, N.;
   Kano, R.; Kubo, M.; Ishikawa, S.; Bando, T.; Hara, H.; Suematsu, Y.;
   Winebarger, A.; Kobayashi, K.; Auchère, F.; Trujillo Bueno, J.
Bibcode: 2016SPIE.9905E..3DG
Altcode:
  The Chromospheric Lyman-Alpha Spectro-Polarimeter (CLASP) is a
  sounding-rocket instrument developed at the National Astronomical
  Observatory of Japan (NAOJ) as a part of an international
  collaboration. The instrument main scientific goal is to achieve
  polarization measurement of the Lyman-α line at 121.56 nm emitted from
  the solar upper-chromosphere and transition region with an unprecedented
  0.1% accuracy. The optics are composed of a Cassegrain telescope
  coated with a "cold mirror" coating optimized for UV reflection and
  a dual-channel spectrograph allowing for simultaneous observation of
  the two orthogonal states of polarization. Although the polarization
  sensitivity is the most important aspect of the instrument, the spatial
  and spectral resolutions of the instrument are also crucial to observe
  the chromospheric features and resolve the Ly-α profiles. A precise
  alignment of the optics is required to ensure the resolutions, but
  experiments under vacuum conditions are needed since Ly-α is absorbed
  by air, making the alignment experiments difficult. To bypass this
  issue, we developed methods to align the telescope and the spectrograph
  separately in visible light. We explain these methods and present
  the results for the optical alignment of the CLASP telescope and
  spectrograph. We then discuss the combined performances of both parts
  to derive the expected resolutions of the instrument, and compare them
  with the flight observations performed on September 3<SUP>rd</SUP> 2015.

Title: Chromospheric LAyer SpectroPolarimeter (CLASP2)
Authors: Narukage, Noriyuki; McKenzie, David E.; Ishikawa, Ryoko;
   Trujillo-Bueno, Javier; De Pontieu, Bart; Kubo, Masahito; Ishikawa,
   Shin-nosuke; Kano, Ryouhei; Suematsu, Yoshinori; Yoshida, Masaki;
   Rachmeler, Laurel A.; Kobayashi, Ken; Cirtain, Jonathan W.; Winebarger,
   Amy R.; Asensio Ramos, Andres; del Pino Aleman, Tanausu; Štępán,
   Jiri; Belluzzi, Luca; Larruquert, Juan Ignacio; Auchère, Frédéric;
   Leenaarts, Jorrit; Carlsson, Mattias J. L.
Bibcode: 2016SPIE.9905E..08N
Altcode:
  The sounding rocket Chromospheric Lyman-Alpha SpectroPolarimeter
  (CLASP) was launched on September 3rd, 2015, and successfully detected
  (with a polarization accuracy of 0.1 %) the linear polarization signals
  (Stokes Q and U) that scattering processes were predicted to produce
  in the hydrogen Lyman-alpha line (Lyα 121.567 nm). Via the Hanle
  effect, this unique data set may provide novel information about the
  magnetic structure and energetics in the upper solar chromosphere. The
  CLASP instrument was safely recovered without any damage and we have
  recently proposed to dedicate its second flight to observe the four
  Stokes profiles in the spectral region of the Mg II h and k lines
  around 280 nm; in these lines the polarization signals result from
  scattering processes and the Hanle and Zeeman effects. Here we describe
  the modifications needed to develop this new instrument called the
  "Chromospheric LAyer SpectroPolarimeter" (CLASP2).

Title: Development of a near-infrared detector and a fiber-optic
    integral field unit for a space solar observatory SOLAR-C
Authors: Katsukawa, Yukio; Kamata, Yukiko; Anan, Tetsu; Hara,
   Hirohisa; Suematsu, Yoshinori; Bando, Takamasa; Ichimoto, Kiyoshi;
   Shimizu, Toshifumi
Bibcode: 2016SPIE.9904E..5IK
Altcode:
  We are developing a high sensitivity and fast readout near-infrared
  (NIR) detector and an integral field unit (IFU) for making
  spectro-polarimetric observations of rapidly varying chromospheric
  spectrum lines, such as He I 1083 nm and Ca II 854 nm, in the
  next space-based solar mission SOLAR-C. We made tests of a 1.7 μm
  cutoff H2RG detector with the SIDECAR ASIC for the application in
  SOLAR-C. It's important to verify its perfor- mance in the temperature
  condition around -100 °C, which is hotter than the typical temperature
  environment used for a NIR detector. We built a system for testing the
  detector between -70 °C and -140 °C. We verified linearity, read-out
  noise, and dark current in both the slow and fast readout modes. We
  found the detector has to be cooled down lower than -100 °C because
  of significant increase of the number of hot pixels in the hotter
  environment. The compact and polarization maintenance IFU was designed
  using fiber-optic ribbons consisting of rectangular cores which exhibit
  good polarization maintenance. A Silicone adhesive DC-SE9187L was used
  to hold the fragile fiber-optic ribbons in a metal housing. Polarization
  maintenance property was confirmed though polarization calibration
  as well as temperature control are required to suppress polarization
  crosstalk and to achieve the polarization accuracy in SOLAR-C.

Title: Analysis of spatially deconvolved polar faculae
Authors: Quintero Noda, C.; Suematsu, Y.; Ruiz Cobo, B.; Shimizu,
   T.; Asensio Ramos, A.
Bibcode: 2016MNRAS.460..956Q
Altcode: 2016MNRAS.tmp..838Q; 2016arXiv160500330Q
  Polar faculae are bright features that can be detected in
  solar limb observations and they are related to magnetic field
  concentrations. Although there are a large number of works studying
  them, some questions about their nature as their magnetic properties
  at different heights are still open. Thus, we aim to improve the
  understanding of solar polar faculae. In that sense, we infer
  the vertical stratification of the temperature, gas pressure,
  line-of-sight velocity and magnetic field vector of polar faculae
  regions. We performed inversions of the Stokes profiles observed
  with Hinode/Spectropolarimeter after removing the stray light
  contamination produced by the spatial point spread function of the
  telescope. Moreover, after solving the azimuth ambiguity, we transform
  the magnetic field vector to local solar coordinates. The obtained
  results reveal that the polar faculae are constituted by hot plasma with
  low line-of-sight velocities and single polarity magnetic fields in the
  kilogauss range that are nearly perpendicular to the solar surface. We
  also found that the spatial location of these magnetic fields is
  slightly shifted respect to the continuum observations towards the
  disc centre. We believe that this is due to the hot wall effect that
  allows detecting photons that come from deeper layers located closer
  to the solar limb.

Title: Development of compact metal-mirror image slicer unit for
    optical telescope of the SOLAR-C mission
Authors: Suematsu, Y.; Saito, K.; Koyama, M.; Enokida, Y.; Okura,
   Y.; Nakayasu, T.; Sukegawa, T.
Bibcode: 2016SPIE.9904E..11S
Altcode:
  To realize an integral field unit (IFU) for a one-meter class optical
  telescope (SUVIT) on board Japanese next solar mission (SOLAR-C),
  we studied an optical design and manufacturing method to attain high
  optical performances for IFU, using a novel manufacturing technique
  developed by Canon. The IFU consists of micro-image slicer of 45 arrayed
  30-micron-thick metal mirrors and a pseudo-pupil mirror array for
  making three pseudo-slits, providing possible optical configuration
  for a coexistence with a usual slit spectrograph without movable
  mechanism. The IFU mirrors were deposited by a protected silver coating
  for high reflectivity in visible and near IR wavelength region. We
  present the optical design, performance of prototype IFU and space
  qualification tests of the silver coating.

Title: Spectropolarimetric capabilities of Ca II 8542 Å line
Authors: Quintero Noda, C.; Shimizu, T.; de la Cruz Rodríguez, J.;
   Katsukawa, Y.; Ichimoto, K.; Anan, T.; Suematsu, Y.
Bibcode: 2016MNRAS.459.3363Q
Altcode: 2016MNRAS.tmp..667Q; 2016arXiv160404957Q
  The next generation of space- and ground-based solar missions aim
  to study the magnetic properties of the solar chromosphere using the
  infrared Ca II lines and the He I 10830 Å line. The former seem to be
  the best candidates to study the stratification of magnetic fields in
  the solar chromosphere and their relation to the other thermodynamical
  properties underlying the chromospheric plasma. The purpose of this
  work is to provide a detailed analysis of the diagnostic capabilities
  of the Ca II 8542 Å line, anticipating forthcoming observational
  facilities. We study the sensitivity of the Ca II 8542 Å line
  to perturbations applied to the physical parameters of reference
  semi-empirical 1D model atmospheres using response functions and we
  make use of 3D magnetohydrodynamics simulations to examine the expected
  polarization signals for moderate magnetic field strengths. Our results
  indicate that the Ca II 8542 Å line is mostly sensitive to the layers
  enclosed in the range log τ = [0, -5.5], under the physical conditions
  that are present in our model atmospheres. In addition, the simulated
  magnetic flux tube generates strong longitudinal signals in its centre
  and moderate transversal signals, due to the vertical expansion of
  magnetic field lines, in its edge. Thus, observing the Ca II 8542 Å
  line we will be able to infer the 3D geometry of moderate magnetic
  field regions.

Title: Spectro-polarimetric observation in UV with CLASP to probe
    the chromosphere and transition region
Authors: Kano, Ryouhei; Ishikawa, Ryohko; Winebarger, Amy R.; Auchère,
   Frédéric; Trujillo Bueno, Javier; Narukage, Noriyuki; Kobayashi,
   Ken; Bando, Takamasa; Katsukawa, Yukio; Kubo, Masahito; Ishikawa,
   Shin-Nosuke; Giono, Gabriel; Hara, Hirohisa; Suematsu, Yoshinori;
   Shimizu, Toshifumi; Sakao, Taro; Tsuneta, Saku; Ichimoto, Kiyoshi;
   Goto, Motoshi; Cirtain, Jonathan W.; De Pontieu, Bart; Casini, Roberto;
   Manso Sainz, Rafael; Asensio Ramos, Andres; Stepan, Jiri; Belluzzi,
   Luca; Carlsson, Mats
Bibcode: 2016SPD....4710107K
Altcode:
  The Chromospheric Lyman-Alpha Spectro-Polarimeter (CLASP) is a NASA
  sounding-rocket experiment that was performed in White Sands in
  the US on September 3, 2015. During its 5-minute ballistic flight,
  CLASP successfully made the first spectro-polarimetric observation in
  the Lyman-alpha line (121.57 nm) originating in the chromosphere and
  transition region. Since the Lyman-alpha polarization is sensitive
  to magnetic field of 10-100 G by the Hanle effect, we aim to infer
  the magnetic field information in such upper solar atmosphere with
  this experiment.The obtained CLASP data showed that the Lyman-alpha
  scattering polarization is about a few percent in the wings and
  the order of 0.1% in the core near the solar limb, as it had been
  theoretically predicted, and that both polarization signals have a
  conspicuous spatio-temporal variability. CLASP also observed another
  upper-chromospheric line, Si III (120.65 nm), whose critical field
  strength for the Hanle effect is 290 G, and showed a measurable
  scattering polarization of a few % in this line. The polarization
  properties of the Si III line could facilitate the interpretation of
  the scattering polarization observed in the Lyman-alpha line.In this
  presentation, we would like to show how the upper chromosphere and
  transition region are seen in the polarization of these UV lines and
  discuss the possible source of these complicated polarization signals.

Title: Development of the Universal Tunable Filter and High-resolution
    Imaging Observation with the Fuxian Solar Observatory
Authors: Hagino, M.; Ichimoto, K.; Ueno, S.; Kimura, G.; Otsuji, K.;
   Kitai, R.; Zhong, L.; Xu, Z.; Shinoda, K.; Hara, H.; Suematsu, Y.;
   Shimizu, T.
Bibcode: 2016ASPC..504..103H
Altcode:
  We have developed a new narrow-band universal tunable filter to perform
  imaging spectroscopy of the solar chromosphere. The development stage
  of the filter has been almost finished and we shifted to the scientific
  observation phase by using large grand-based telescopes. Using the
  filter, a series of high-resolution images were obtained with the 1m
  vacuum solar telescope at the Fuxian Solar Observatory. We succeeded in
  observing several flares and fine structures of the chromospheric layer.

Title: The SOLAR-C Mission: Science Objectives and Current Status
Authors: Suematsu, Y.; Solar-C Working Group
Bibcode: 2016ASPC..504..299S
Altcode:
  The SOLAR-C is a Japan-led international solar mission for mid-2020s
  designed to investigate the magnetic activities of the Sun, focusing on
  the study in heating and dynamical phenomena of the chromosphere and
  corona, and to advance algorithms for predicting short and long term
  solar magnetic activities. For these purposes, SOLAR-C will carry three
  dedicated instruments; the Solar UV-Vis-IR Telescope (SUVIT), the EUV
  Spectroscopic Telescope (EUVST) and the High Resolution Coronal Imager
  (HCI), to jointly observe the entire visible solar atmosphere with
  essentially the same high spatial resolution (0.1"-0.3"), performing
  high resolution spectroscopic measurements over all atmospheric regions
  and spectro-polarimetric measurements from the photosphere through
  the upper chromosphere. SOLAR-C will also contribute to understand
  the solar influence on the Sun-Earth environments with synergetic
  wide-field observations from ground-based and other space missions.

Title: Analysis of horizontal flows in the solar granulation
Authors: Quintero Noda, C.; Shimizu, T.; Suematsu, Y.
Bibcode: 2016MNRAS.457.1703Q
Altcode: 2016arXiv160103814Q
  Solar limb observations sometimes reveal the presence of a satellite
  lobe in the blue wing of the Stokes I profile from pixels belonging to
  granules. The presence of this satellite lobe has been associated in
  the past to strong line-of-sight gradients and, as the line-of-sight
  component is almost parallel to the solar surface, to horizontal
  granular flows. We aim to increase the knowledge about these horizontal
  flows studying a spectropolarimetric observation of the north solar
  pole. We will make use of two state of the art techniques, the spatial
  deconvolution procedure that increases the quality of the data removing
  the stray light contamination, and spectropolarimetric inversions that
  will provide the vertical stratification of the atmospheric physical
  parameters where the observed spectral lines form. We inverted the
  Stokes profiles using a two component configuration, obtaining that
  one component is strongly blueshifted and displays a temperature
  enhancement at upper photospheric layers while the second component has
  low redshifted velocities and it is cool at upper layers. In addition,
  we examined a large number of cases located at different heliocentric
  angles, finding smaller velocities as we move from the centre to the
  edge of the granule. Moreover, the height location of the enhancement
  on the temperature stratification of the blueshifted component also
  evolves with the spatial location on the granule being positioned on
  lower heights as we move to the periphery of the granular structure.

Title: The SOLAR-C Mission
Authors: Suematsu, Y.
Bibcode: 2015AGUFMSH21C..03S
Altcode:
  The Solar-C is a Japan-led international solar mission planned to
  be launched in mid2020. It is designed to investigate the magnetic
  activities of the Sun, focusing on the study in heating and dynamical
  phenomena of the chromosphere and corona, and also to develop an
  algorithm for predicting short and long term solar evolution. Since
  it has been revealed that the different parts of the magnetized
  solar atmosphere are essentially coupled, the SOLAR-C should tackle
  the spatial scales and temperature regimes that need to be observed
  in order to achieve a comprehensive physical understanding of this
  coupling. The science of Solar-C will greatly advance our understanding
  of the Sun, of basic physical processes operating throughout the
  universe. To dramatically improve the situation, SOLAR-C will carry
  three dedicated instruments; the Solar UV-Vis-IR Telescope (SUVIT),
  the EUV Spectroscopic Telescope (EUVST) and the High Resolution
  Coronal Imager (HCI), to jointly observe the entire visible solar
  atmosphere with essentially the same high spatial resolution (0.1-0.3
  arcsec), performing high resolution spectroscopic measurements over
  all atmospheric regions and spectro-polarimetric measurements from
  the photosphere through the upper chromosphere. In addition, Solar-C
  will contribute to our understanding on the influence of the Sun-Earth
  environments with synergetic wide-field observations from ground-based
  and other space missions. Some leading science objectives and the
  mission concept, including designs of the three instruments aboard
  SOLAR-C will be presented.

Title: Development of precision Wolter mirrors for future solar
    x-ray observations
Authors: Sakao, Taro; Matsuyama, Satoshi; Kime, Ayumi; Goto, Takumi;
   Nishihara, Akihiko; Nakamori, Hiroki; Yamauchi, Kazuto; Kohmura,
   Yoshiki; Miyake, Akira; Hashizume, Hirokazu; Maezawa, Tadakazu;
   Suematsu, Yoshinori; Narukage, Noriyuki
Bibcode: 2015SPIE.9603E..0US
Altcode:
  High resolution imagery of the solar X-ray corona provides a
  crucial key to understand dynamics and heating processes of plasma
  particles there. However, X-ray imagery of the Sun with sub-arcsecond
  resolution has yet to be conducted due to severe technical difficulty in
  fabricating precision Wolter mirrors. For future X-ray observations of
  the Sun's corona, we are attempting to realize precision Wolter mirrors
  with sub-arcsecond resolution by adopting advanced surface polish and
  metrology methods based on nano-technology to sector mirrors which
  consist of a portion of an entire annulus. Following fabrication
  of the first engineering mirror and subsequent evaluation on the
  X-ray focusing performance in 2013, the second engineering mirror
  was made with improvements in both precision polish and metrology
  introduced. Measurement of focusing performance on the second mirror
  at SPring-8 synchrotron facility with 8 keV X-rays has demonstrated
  that the FWHM size of the PSF core reached down to 0.2" while its HPD
  (Half Power Diameter) size remained at ~3" due to the presence of
  small-angle scatter just outside of the core. Also, there was notable
  difference in the focal length between sagittal and meridional focusing
  which could have been caused by an error in the sag in the meridional
  direction of &lt;10 nm in the mirror area. Further improvements to
  overcome these issues have been planned for the next engineering mirror.

Title: CLASP: A UV Spectropolarimeter on a Sounding Rocket for
    Probing theChromosphere-Corona Transition Regio
Authors: Ishikawa, Ryohko; Kano, Ryouhei; Winebarger, Amy; Auchere,
   Frederic; Trujillo Bueno, Javier; Bando, Takamasa; Narukage,
   Noriyuki; Kobayashi, Ken; Katsukawa, Yukio; Kubo, Masahito; Ishikawa,
   Shin-nosuke; Giono, Gabriel; Tsuneta, Saku; Hara, Hirohisa; Suematsu,
   Yoshinori; Shimizu, Toshifumi; Sakao, Taro; Ichimoto, Kiyoshi;
   Cirtain, Jonathan; De Pontieu, Bart; Casini, Roberto; Manso Sainz,
   Rafael; Asensio Ramos, Andres; Stepan, Jiri; Belluzzi, Luca
Bibcode: 2015IAUGA..2254536I
Altcode:
  The wish to understand the energetic phenomena of the outer solar
  atmosphere makes it increasingly important to achieve quantitative
  information on the magnetic field in the chromosphere-corona
  transition region. To this end, we need to measure and model the
  linear polarization produced by scattering processes and the Hanle
  effect in strong UV resonance lines, such as the hydrogen Lyman-alpha
  line. A team consisting of Japan, USA, Spain, France, and Norway has
  been developing a sounding rocket experiment called the Chromospheric
  Lyman-alpha Spectro-Polarimeter (CLASP). The aim is to detect the
  scattering polarization produced by anisotropic radiation pumping in
  the hydrogen Lyman-alpha line (121.6 nm), and via the Hanle effect to
  try to constrain the magnetic field vector in the upper chromosphere
  and transition region. In this talk, we will present an overview
  of our CLASP mission, its scientific objectives, ground tests made,
  and the latest information on the launch planned for the Summer of 2015.

Title: Photon Mean Free Paths, Scattering, and Ever-Increasing
    Telescope Resolution
Authors: Judge, P. G.; Kleint, L.; Uitenbroek, H.; Rempel, M.;
   Suematsu, Y.; Tsuneta, S.
Bibcode: 2015SoPh..290..979J
Altcode: 2014arXiv1409.7866J; 2015SoPh..tmp....3J
  We revisit an old question: what are the effects of observing stratified
  atmospheres on scales below a photon mean free path λ? The mean free
  path of photons emerging from the solar photosphere and chromosphere
  is ≈ 10<SUP>2</SUP> km. Using current 1 m-class telescopes, λ is
  on the order of the angular resolution. But the Daniel K. Inoue Solar
  Telescope will have a diffraction limit of 0.020″ near the atmospheric
  cutoff at 310 nm, corresponding to 14 km at the solar surface. Even
  a small amount of scattering in the source function leads to physical
  smearing due to this solar "fog", with effects similar to a degradation
  of the telescope point spread function. We discuss a unified picture
  that depends simply on the nature and amount of scattering in the
  source function. Scalings are derived from which the scattering in the
  solar atmosphere can be transcribed into an effective Strehl ratio,
  a quantity useful to observers. Observations in both permitted (e.g.,
  Fe I 630.2 nm) and forbidden (Fe I 525.0 nm) lines will shed light on
  both instrumental performance as well as on small-scale structures in
  the solar atmosphere.

Title: Photospheric Flow Field Related to the Evolution of the Sun's
    Polar Magnetic Patches Observed by Hinode Solar Optical Telescope
Authors: Kaithakkal, Anjali John; Suematsu, Y.; Kubo, M.; Iida, Y.;
   Shiota, D.; Tsuneta, S.
Bibcode: 2015ApJ...799..139K
Altcode: 2014arXiv1412.8023K
  We investigated the role of photospheric plasma motions in the formation
  and evolution of polar magnetic patches using time-sequence observations
  with high spatial resolution. The observations were obtained with
  the spectropolarimeter on board the Hinode satellite. From the
  statistical analysis using 75 magnetic patches, we found that they are
  surrounded by strong converging, supergranulation associated flows
  during their apparent lifetime and that the converging flow around
  the patch boundary is better observed in the Doppler velocity profile
  in the deeper photosphere. Based on our analysis, we suggest that the
  like-polarity magnetic fragments in the polar region are advected and
  clustered by photospheric converging flows, thereby resulting in the
  formation of polar magnetic patches. Our observations show that, in
  addition to direct cancellation, magnetic patches decay by fragmentation
  followed by unipolar disappearance or unipolar disappearance without
  fragmentation. It is possible that the magnetic patches of existing
  polarity fragment or diffuse away into smaller elements and eventually
  cancel out with opposite polarity fragments that reach the polar region
  around the solar cycle maximum. This could be one of the possible
  mechanisms by which the existing polarity decays during the reversal
  of the polar magnetic field.

Title: Fine-Scale Structure of Solar Polar Faculae and their relation
    to Magnetic Patches
Authors: Suematsu, Y.; Kaithakkal, A. J.
Bibcode: 2014AGUFMSH31C..07S
Altcode:
  The fine-scale structure and dynamics of solar polar faculae were
  studied using Hinode/SOT spectro-polarimetric and filtergraphic
  observations at polar regions. It is revealed that polar magnetic
  patches of large flux have substructures, with a few small faculae
  in the much larger patches. It was also found that faculae tend to
  have higher intrinsic magnetic field strengths compared with the
  non-facular regions inside the associated magnetic patches. G-band
  images reveal much thinner facular structures of close to 0.1 arcsec and
  the faculae appear as a cluster of thin tapered tube-like structures;
  individual size is about 0.2 x 0.5 arcsec, reaching the maximum closer
  mid-way to the limb, are likely projected on the limb-side neighboring
  granules with center-ward dark lanes. Typical lifetime of each facular
  elements is about five minutes, showing side-way motion during the
  life. Corresponding bright fine elongated structures are seen in Ca
  II H, although such structures are more numerous and therefore there
  does not always exist one-to-one correspondence of Ca II H bright
  structures with the G-band facular elements. In H-alpha and Na I D line
  wing, fibril structure emanating limb-ward from the faulae and Ca II H
  bright regions. Those facts imply that the polar faculae appear in the
  root of intense vertically-oriented thin magnetic flux tubes which are
  consistent with the result from the magnetic properties reduced from
  the spectro-polarimetry. Those results suggest that the Spruit's hot
  wall effect explains the appearance of faculae in intense vertically
  oriented flux tube whose formation is dynamically changing.

Title: Precision VUV Spectro-Polarimetry for Solar Chromospheric
    Magnetic Field Measurements
Authors: Ishikawa, R.; Bando, T.; Hara, H.; Ishikawa, S.; Kano, R.;
   Kubo, M.; Katsukawa, Y.; Kobiki, T.; Narukage, N.; Suematsu, Y.;
   Tsuneta, S.; Aoki, K.; Miyagawa, K.; Ichimoto, K.; Kobayashi, K.;
   Auchère, F.; Clasp Team
Bibcode: 2014ASPC..489..319I
Altcode:
  The Chromospheric Lyman-Alpha Spectro-Polarimeter (CLASP) is a VUV
  spectro-polarimeter optimized for measuring the linear polarization
  of the Lyman-α line (121.6 nm) to be launched in 2015 with NASA's
  sounding rocket (Ishikawa et al. 2011; Narukage et al. 2011; Kano et
  al. 2012; Kobayashi et al. 2012). With this experiment, we aim to (1)
  observe the scattering polarization in the Lyman-α line, (2) detect
  the Hanle effect, and (3) assess the magnetic fields in the upper
  chromosphere and transition region for the first time. The polarization
  measurement error consists of scale error δ a (error in amplitude
  of linear polarization), azimuth error Δφ (error in the direction
  of linear polarization), and spurious polarization ɛ (false linear
  polarization signals). The error ɛ should be suppressed below 0.1%
  in the Lyman-α core (121.567 nm ±0.02 nm), and 0.5% in the Lyman-α
  wing (121.567 nm ±0.05 nm), based on our scientific requirements shown
  in Table 2 of Kubo et al. (2014). From scientific justification, we
  adopt Δ φ&lt;2° and δ a&lt;10% as the instrument requirements. The
  spectro-polarimeter features a continuously rotating MgF<SUB>2</SUB>
  waveplate (Ishikawa et al. 2013), a dual-beam spectrograph with a
  spherical grating working also as a beam splitter, and two polarization
  analyzers (Bridou et al. 2011), which are mounted at 90 degree from
  each other to measure two orthogonal polarization simultaneously. For
  the optical layout of the CLASP instrument, see Figure 3 in Kubo et
  al. (2014). Considering the continuous rotation of the half-waveplate,
  the modulation efficiency is 0.64 both for Stokes Q and U. All the raw
  data are returned and demodulation (successive addition or subtraction
  of images) is done on the ground. <P />We control the CLASP polarization
  performance in the following three steps. First, we evaluate the
  throughput and polarization properties of each optical component in
  the Lyman-α line, using the Ultraviolet Synchrotron ORbital Radiation
  Facility (UVSOR) at the Institute for Molecular Science. The second
  step is polarization calibration of the spectro-polarimeter after
  alignment. Since the spurious polarization caused by the axisymmetric
  telescope is estimated to be negligibly small because of the symmetry
  (Ishikawa et al. 2014), we do not perform end-to-end polarization
  calibration. As the final step, before the scientific observation near
  the limb, we make a short observation at the Sun center and verify
  the polarization sensitivity, because the scattering polarization
  is expected to be close to zero at the Sun center due to symmetric
  geometry. In order to clarify whether we will be able to achieve the
  required polarization sensitivity and accuracy via these steps, we
  exercise polarization error budget, by investigating all the possible
  causes and their magnitudes of polarization errors, all of which are not
  necessarily verified by the polarization calibration. Based on these
  error budgets, we conclude that a polarization sensitivity of 0.1% in
  the line core, δ a&lt;10% and Δ φ&lt;2° can be achieved combined
  with the polarization calibration of the spectro-polarimeter and the
  onboard calibration at the Sun center(refer to Ishikawa et al. 2014,
  for the detail). <P />We are currently conducting verification tests
  of the flight components and development of the UV light source for
  the polarization calibration. From 2014 spring, we will begin the
  integration, alignment, and calibration. We will update the error
  budgets throughout the course of these tests.

Title: A Sounding Rocket Experiment for the Chromospheric Lyman-Alpha
    Spectro-Polarimeter (CLASP)
Authors: Kubo, M.; Kano, R.; Kobayashi, K.; Bando, T.; Narukage, N.;
   Ishikawa, R.; Tsuneta, S.; Katsukawa, Y.; Ishikawa, S.; Suematsu, Y.;
   Hara, H.; Shimizu, T.; Sakao, T.; Ichimoto, K.; Goto, M.; Holloway,
   T.; Winebarger, A.; Cirtain, J.; De Pontieu, B.; Casini, R.; Auchère,
   F.; Trujillo Bueno, J.; Manso Sainz, R.; Belluzzi, L.; Asensio Ramos,
   A.; Štěpán, J.; Carlsson, M.
Bibcode: 2014ASPC..489..307K
Altcode:
  A sounding-rocket experiment called the Chromospheric Lyman-Alpha
  Spectro-Polarimeter (CLASP) is presently under development to measure
  the linear polarization profiles in the hydrogen Lyman-alpha (Lyα)
  line at 121.567 nm. CLASP is a vacuum-UV (VUV) spectropolarimeter to aim
  for first detection of the linear polarizations caused by scattering
  processes and the Hanle effect in the Lyα line with high accuracy
  (0.1%). This is a fist step for exploration of magnetic fields in
  the upper chromosphere and transition region of the Sun. Accurate
  measurements of the linear polarization signals caused by scattering
  processes and the Hanle effect in strong UV lines like Lyα are
  essential to explore with future solar telescopes the strength
  and structures of the magnetic field in the upper chromosphere and
  transition region of the Sun. The CLASP proposal has been accepted by
  NASA in 2012, and the flight is planned in 2015.

Title: Large aperture solar optical telescope and instruments for
    the SOLAR-C mission
Authors: Suematsu, Y.; Katsukawa, Y.; Hara, H.; Kano, R.; Shimizu,
   T.; Ichimoto, K.
Bibcode: 2014SPIE.9143E..1PS
Altcode:
  A large aperture solar optical telescope and its instruments
  for the SOLAR-C mission are under study to provide the critical
  physical parameters in the lower solar atmosphere and to resolve the
  mechanism of magnetic dynamic events happening there and in the upper
  atmosphere as well. For the precise magnetic field measurements and
  high angular resolution in wide wavelength region, covering FOV of 3
  arcmin x3 arcmin, an entrance aperture of 1.4 m Gregorian telescope is
  proposed. Filtergraphs are designed to realize high resolution imaging
  and pseudo 2D spectro-polarimetry in several magnetic sensitive lines of
  both photosphere and chromosphere. A full stokes polarimetry is carried
  out at three magnetic sensitive lines with a four-slit spectrograph
  of 2D image scanning mechanism. We present a progress in optical and
  structural design of SOLAR-C large aperture optical telescope and its
  observing instruments which fulfill science requirements.

Title: Development of micro image slicer of integral field unit for
    spaceborne solar spectrograph
Authors: Suematsu, Y.; Sukegawa, T.; Okura, Y.; Nakayasu, T.; Enokida,
   Y.; Koyama, M.; Saito, K.; Ozaki, S.; Tsuneta, S.
Bibcode: 2014SPIE.9151E..1SS
Altcode:
  We present an innovative optical design for image slicer integral field
  unit (IFU) and manufacturing method which overcome optical limitation of
  metallic mirrors. Our IFU consists of micro image slicer of 45 arrayed
  highly-narrow flat metallic mirrors and a pseudo pupil mirror array
  of off-axis conic aspheres forming three pseudo slits of re-arranged
  slicer images. A prototype IFU demonstrates their optical quality high
  enough for a visible light spectrograph. The each slicer mirror is 1.58
  mm in length and 30μm in width with surface roughness &lt; 1 nm rms,
  edge sharpness &lt; 0.1μm, etc. This IFU is small-sized and can be
  implemented in a multi-slit spectrograph without any moving mechanism
  and fore optics in which one slit is real and the others are of pseudo
  slits from the IFU. Those properties are well suitable for space-borne
  spectrograph to be aboard such as a next Japanese solar mission SOLAR-C.

Title: Current progress of optical alignment procedure of CLASP's
    Lyman-alpha polarimetry instrument
Authors: Giono, G.; Ishikawa, R.; Katsukawa, Y.; Bando, T.; Kano, R.;
   Suematsu, Y.; Narukage, N.; Sakao, Taro; Kobayashi, K.; Auchère, F.
Bibcode: 2014SPIE.9144E..3EG
Altcode:
  The Chromospheric Lyman-Alpha Spectro-Polarimeter (CLASP) is a
  sounding-rocket instrument currently under development at the
  National Astronomical Observatory of Japan (NAOJ) as a part of an
  international collaboration. CLASP's optics are composed of a Cassegrain
  telescope and a spectro-polarimeter which are designed to achieve an
  unprecedentedly accurate polarization measurement of the Ly-α line
  at 121.6nm emitted from the solar upper-chromosphere and transition
  region. CLASP's first flight is scheduled for August 2015. Reaching
  such accuracy requires a careful alignment of the optical elements
  to optimize the image quality at 121.6 nm. However Ly-α is absorbed
  by air and therefore the optics alignment has to be done under vacuum
  condition which makes any experiment difficult. To bypass this issue,
  we proposed to align the telescope and the spectrograph separately
  in visible light. Hence we present our alignment procedure for both
  telescope and spectro-polarimeter. We will explain details about the
  telescope preliminary alignment before mirrors coating, which was done
  in April 2014, present the telescope combined optical performance
  and compare them to CLASP tolerance. Then we will present details
  about an experiment designed to confirm our alignment procedure for
  the CLASP spectro-polarimeter. We will discuss the resulting image
  quality achieved during this experiment and the lessons learned.

Title: The soft x-ray photon-counting telescope for solar observations
Authors: Sakao, Taro; Narukage, Noriyuki; Suematsu, Yoshinori;
   Watanabe, Kyoko; Shimojo, Masumi; Imada, Shinsuke; Ishikawa,
   Shin-nosuke; DeLuca, Edward E.
Bibcode: 2014SPIE.9144E..3DS
Altcode:
  We present overview and development activities of a soft X-ray
  photon-counting spectroscopic imager for the solar corona that
  we conceive as a possible scientific payload for future space
  solar missions including Japanese Solar-C. The soft X-ray imager
  will employ a Wolter I grazing-incidence sector mirror with which
  images of the corona (1 MK to beyond 10 MK) will be taken with
  the highest-ever angular resolution (0.5"/pixel for a focal length
  of 4 m) as a solar Xray telescope. In addition to high-resolution
  imagery, we attempt to implement photon-counting capability for the
  imager by employing a backside-illuminated CMOS image sensor as the
  focal-plane device. Imaging-spectroscopy of the X-ray corona will be
  performed for the first time in the energy range from ~0.5 keV up to
  10 keV. The imaging-spectroscopic observations with the soft X-ray
  imager will provide a noble probe for investigating mechanism(s) of
  magnetic reconnection and generation of supra-thermal (non-thermal)
  electrons associated with flares. Ongoing development activities in
  Japan towards the photon-counting imager is described with emphasis
  on that for sub-arcsecond-resolution grazing-incidence mirrors.

Title: Development of a universal tunable filter for future solar
    observations
Authors: Hagino, M.; Ichimoto, K.; Kimura, G.; Nakatani, Y.; Kawate,
   T.; Shinoda, K.; Suematsu, Y.; Hara, H.; Shimizu, T.
Bibcode: 2014SPIE.9151E..5VH
Altcode:
  We have developed a new narrowband tunable filter to perform imaging
  spectroscopy of the solar chromosphere. Using Liquid Crystal Variable
  Retarders (LCVRs) as the tuning elements for wavelength, wide-band
  polarizers and super achromatic half-wave plates, it is possible to make
  high speed tuning (about 0.1Sec), to exclude mechanical drives (and oil
  tank), and to cover a wide wavelength range (510-100nm). This filter
  builds up with seven stages each consisting of a pair of calcites,
  LCVR, half-wave plates and linear polarizer. The full width at half
  maximum (FWHM) of the filter transmission is about 0.025nm at 656.3nm.We
  demonstrate that the concept of the universal tunable filter using the
  LCVR's as tuning elements is highly promising for future application
  to space mission and ground based observations.

Title: UV spectropolarimeter design for precise polarization
    measurement and its application to the CLASP for exploration of
    magnetic fields in solar atmosphere
Authors: Narukage, Noriyuki; Katsukawa, Yukio; Hara, Hirohisa; Kubo,
   Masahito; Auchere, Frederic; Ishikawa, Ryohko; Kano, Ryouhei; Bando,
   Takamasa; Ishikawa, Shin-nosuke; Suematsu, Yoshinori; Tsuneta, Saku
Bibcode: 2014cosp...40E2232N
Altcode:
  In order to measure the magnetic field in the region where the
  hot plasma from 10 (4) K to 10 (6) K is occupied, e.g., for solar
  atmosphere, the polarimetric measurements in ultra violet (UV)
  with 0.1% accuracy are required. In this paper, we propose a new
  UV spectropolarimeter design with 0.1% sensitivity in polarization
  measurement. This spectropolarimeter has two devices for the 0.1%
  accuracy. First, all optical components except the waveplate are the
  reflective type ones that can be equipped with the high reflectivity
  coating for the high throughput. Secondly, it equips the optically
  symmetric dual channels to measure the orthogonal linear polarization
  state simultaneously, using a concave diffraction grating as both the
  spectral dispersion element and the beam splitter. These two devices
  make the spurious polarizations caused by the photon noise, by the
  intensity variation of the observation target, and, by the instrument
  itself, enough small to achieve the 0.1% accuracy in polarization
  measurement. The spectropolarimeter thus designed is currently under
  fabrication for the sounding rocket project of Chromospheric Lyman-Alpha
  SpectroPolarimeter (CLASP) that aims at the direct measurement of the
  magnetic fields in solar atmosphere with Lyman-alpha line (121.6 nm)
  for the first time.

Title: The Association of Polar Faculae with Polar Magnetic Patches
    Examined with Hinode Observations
Authors: Kaithakkal, Anjali John; Suematsu, Y.; Kubo, M.; Shiota,
   D.; Tsuneta, S.
Bibcode: 2013ApJ...776..122K
Altcode: 2013arXiv1311.0980K
  The magnetic properties of the Sun's polar faculae are investigated with
  spectropolarimetric observations of the north polar region obtained by
  the Hinode satellite in 2007 September. Polar faculae are embedded in
  nearly all magnetic patches with fluxes greater than 10<SUP>18</SUP>
  Mx, while magnetic patches without polar faculae dominate in the flux
  range below 10<SUP>18</SUP> Mx. The faculae are considerably smaller
  than their parent patches, and single magnetic patches contain single
  or multiple faculae. The faculae in general have higher intrinsic
  magnetic field strengths than the surrounding regions within their
  parent patches. Less than 20% of the total magnetic flux contributed
  by the large (&gt;=10<SUP>18</SUP> Mx) concentrations, which are known
  to be modulated by the solar cycle, is accounted for by the associated
  polar faculae.

Title: Chromospheric Lyman Alpha SpectroPolarimeter: CLASP
Authors: Kobayashi, Ken; Kano, R.; Trujillo Bueno, J.; Winebarger,
   A. R.; Cirtain, J. W.; Bando, T.; De Pontieu, B.; Ishikawa, R.;
   Katsukawa, Y.; Kubo, M.; Narukage, N.; Sakao, T.; Tsuneta, S.;
   Auchère, F.; Asensio Ramos, A.; Belluzzi, L.; Carlsson, M.; Casini,
   R.; Hara, H.; Ichimoto, K.; Manso Sainz, R.; Shimizu, T.; Stepan,
   J.; Suematsu, Y.; Holloway, T.
Bibcode: 2013SPD....44..142K
Altcode:
  The Chromospheric Lyman-Alpha Spectro-Polarimeter (CLASP) is a VUV
  spectropolarimeter optimized for measuring the linear polarization of
  the Lyman-alpha line (121.6 nm). The Lyman-alpha line is predicted to
  show linear polarization caused by atomic scattering in the chromosphere
  and modified by the magnetic field through the Hanle effect. The
  Hanle effect is sensitive to weaker magnetic fields than Zeeman
  effect, and is not canceled by opposing fields, making it sensitive
  to tangled or unresolved magnetic field structures. These factors make
  the Hanle effect a valuable tool for probing the magnetic field in the
  chromosphere above the quiet sun. To meet this goal, CLASP is designed
  to measure linear polarization with 0.1% polarization sensitivity
  at 0.01 nm spectral resolution and 10" spatial resolution. CLASP is
  scheduled to be launched in 2015.

Title: Next space solar observatory SOLAR-C: mission instruments
    and science objectives
Authors: Katsukawa, Y.; Watanabe, T.; Hara, H.; Ichimoto, K.; Kubo,
   M.; Kusano, K.; Sakao, T.; Shimizu, T.; Suematsu, Y.; Tsuneta, S.
Bibcode: 2012IAUSS...6E.207K
Altcode:
  SOLAR-C, the fourth space solar mission in Japan, is under study with a
  launch target of fiscal year 2018. A key concept of the mission is to
  view the photosphere, chromosphere, and corona as one system coupled
  by magnetic fields along with resolving the size scale of fundamental
  physical processes connecting these atmospheric layers. It is especially
  important to study magnetic structure in the chromosphere as an
  interface layer between the photosphere and the corona. The SOLAR-C
  satellite is equipped with three telescopes, the Solar UV-Visible-IR
  Telescope (SUVIT), the EUV/FUV High Throughput Spectroscopic Telescope
  (EUVS/LEMUR), and the X-ray Imaging Telescope (XIT). Observations
  with SUVIT of photospheric and chromospheric magnetic fields make it
  possible to infer three dimensional magnetic structure extending from
  the photosphere to the chromosphere and corona.This helps to identify
  magnetic structures causing magnetic reconnection, and clarify how
  waves are propagated, reflected, and dissipated. Phenomena indicative
  of or byproducts of magnetic reconnection, such as flows and shocks,
  are to be captured by SUVIT and by spectroscopic observations using
  EUVS/LEMUR, while XIT observes rapid changes in temperature distribution
  of plasma heated by shock waves.

Title: Instrument Design of the Large Aperture Solar UV Visible and
    IR Observing Telescope (SUVIT) for the SOLAR-C Mission
Authors: Suematsu, Y.; Katsukawa, Y.; Shimizu, T.; Ichimoto, K.;
   Takeyama, N.
Bibcode: 2012ASPC..463..439S
Altcode:
  We present an instrumental design of one major solar observation payload
  planned for the SOLAR-C mission: the Solar Ultra-violet Visible and
  near IR observing Telescope (SUVIT). The SUVIT is designed to provide
  high-angular-resolution investigation of the lower solar atmosphere,
  from the photosphere to the uppermost chromosphere, with enhanced
  spectroscopic and spectro-polarimetric capability in wide wavelength
  regions from 280 nm (Mg II h&amp;k lines) to 1100 nm (He I 1083 nm
  line) with 1.5 m class aperture and filtergraphic and spectrographic
  instruments.

Title: Association of Polar Faculae with the Polar Magnetic Patches
    as Revealed by Hinode
Authors: Kaithakkal, A. J.; Tsuneta, S.; Suematsu, Y.; Kubo, M.;
   Shiota, D.; Shimojo, M.
Bibcode: 2012AGUFMSH13C2273K
Altcode:
  Polar faculae are small bright features in the polar region of the
  Sun. They are observed with concentrations of magnetic fields. Previous
  studies have shown that the number of polar faculae at latitudes greater
  than 50 degrees has 11-year periodicity like the sunspot cycle, but
  becomes a maximum in the solar minimum period. The aim of this study is
  to understand the magnetic properties of faculae, which are believed
  to be associated with the polar magnetic patches. We analysed data of
  the north polar region taken by the Hinode/SOT spectropolarimeter (SP)
  in September 2007. Accurate measurements of vector magnetic fields
  at high spatial resolution by Hinode/SP for the first time allow us
  to compare polar faculae with polar magnetic fields in detail. The
  continuum intensity map is corrected for limb darkening. There are many
  patchy magnetic field structures in the polar region and thresholds on
  both size and intensity for the patches are applied to automatically
  choose faculae. The definition of magnetic patch is same as in Shiota et
  al. (2012 ApJ). We find that magnetic patches are not uniformly bright
  but contain smaller faculae inside. The following results describe
  the properties of faculae associated with the majority polarity
  patches. Our results show that a positive correlation exists between
  total flux and average intensity contrast of faculae. On average the
  contribution of polar faculae to the total flux of the patch is less
  than 30% and the area occupied by polar faculae with in a patch is
  roughly 20-25%. We find that there are patches without faculae and
  their number is much larger than those with faculae. We also find
  that faculae are present in all the patches with total flux ≥ 10^19
  Mx. Our result show that faculae are polarity independent and hence are
  associated with minority polarity patches as well. But the flux of these
  minority polarity faculae is &lt;10^18 Mx in most of the cases. These
  results suggest that the magnetic patches and polar faculae do not
  have a one-to-one spatial correspondence and have fine structure, and
  may raise a fundamental question on our current understanding on the
  formation of the faculae. Shiota et al. (2012 ApJ) report that there
  are two classes of magnetic patches: small (&lt; 10^18 Mx) and large
  (≥10^18 Mx) of which the large patches contribute to the cyclic
  variation of the polar magnetic flux. This is consistent with the
  concept of faculae as a proxy of the majority polarity magnetic flux.

Title: Science and Instrument Design of 1.5-m Aperture Solar Optical
    Telescope for the SOLAR-C Mission
Authors: Suematsu, Y.; Katsukawa, Y.; Ichimoto, K.; Shimizu, T.
Bibcode: 2012IAUSS...6E.208S
Altcode:
  We present science cases and a design of one of major instruments for
  SOLAR-C mission; 1.5-m-class aperture solar ultra-violet visible and
  near IR observing Telescope (SUVIT). The SOLAR-C mission aims at fully
  understanding dynamism and magnetic nature of the solar atmosphere by
  observing small-scale plasma processes and structures. The SUVIT is
  designed to provide high-angular-resolution investigation of lower
  atmosphere from the photosphere to the uppermost chromosphere with
  enhanced spectroscopic and spectro-polarimetric capability covering
  a wide wavelength region from 280 nm (Mg II h&amp;k) to 1100 nm (He
  I 1083 nm), using focal plane instruments: wide-band and narrow-band
  filtergraphs and a spectrograph for high-precision spectro-polarimetry
  in the solar photospheric and chromospheric lines. We will discuss
  about instrument design to realize the science cases.

Title: Solar Fine-Scale Structures. I. Spicules and Other Small-Scale,
Jet-Like Events at the Chromospheric Level: Observations and Physical
    Parameters
Authors: Tsiropoula, G.; Tziotziou, K.; Kontogiannis, I.; Madjarska,
   M. S.; Doyle, J. G.; Suematsu, Y.
Bibcode: 2012SSRv..169..181T
Altcode: 2012SSRv..tmp...65T; 2012arXiv1207.3956T
  Over the last two decades the uninterrupted, high resolution
  observations of the Sun, from the excellent range of telescopes aboard
  many spacecraft complemented with observations from sophisticated
  ground-based telescopes have opened up a new world producing
  significantly more complete information on the physical conditions of
  the solar atmosphere than before. The interface between the lower solar
  atmosphere where energy is generated by subsurface convection and the
  corona comprises the chromosphere, which is dominated by jet-like,
  dynamic structures, called mottles when found in quiet regions,
  fibrils when found in active regions and spicules when observed at
  the solar limb. Recently, space observations with Hinode have led to
  the suggestion that there should exist two different types of spicules
  called Type I and Type II which have different properties. Ground-based
  observations in the Ca ii H and K filtergrams reveal the existence of
  long, thin emission features called straws in observations close to
  the limb, and a class of short-lived events called rapid blue-shifted
  excursions characterized by large Doppler shifts that appear only
  in the blue wing of the Ca ii infrared line. It has been suggested
  that the key to understanding how the solar plasma is accelerated
  and heated may well be found in the studies of these jet-like,
  dynamic events. However, while these structures are observed and
  studied for more than 130 years in the visible, but also in the UV
  and EUV emission lines and continua, there are still many questions
  to be answered. Thus, despite their importance and a multitude of
  observations performed and theoretical models proposed, questions
  regarding their origin, how they are formed, their physical parameters,
  their association with the underlying photospheric magnetic field, how
  they appear in the different spectral lines, and the interrelationship
  between structures observed in quiet and active regions on the disk
  and at the limb, as well as their role in global processes has not
  yet received definitive answers. In addition, how they affect the
  coronal heating and solar wind need to be further explored. In this
  review we present observations and physical properties of small-scale
  jet-like chromospheric events observed in active and quiet regions,
  on the disk and at the limb and discuss their interrelationship.

Title: Design of large aperture solar optical telescope for the
    SOLAR-C mission
Authors: Suematsu, Y.; Katsukawa, Y.; Hara, H.; Shimizu, T.;
   Ichimoto, K.
Bibcode: 2012SPIE.8442E..25S
Altcode:
  A large aperture optical telescope is planned for the next Japanese
  solar mission SOLAR-C as one of major three observing instruments. The
  optical telescope is designed to provide high-angular-resolution
  investigation of lower atmosphere from the photosphere to the uppermost
  chromosphere with enhanced spectroscopic and spectro-polarimetric
  capability covering a wide wavelength region from 280 nm to 1100
  nm. The opto-mechanical and -thermal performance of the telescope is
  crucial to attain high-quality solar observations and we present a
  study of optical and structural design of the large aperture space
  solar telescope, together with conceptual design of its accompanying
  focal plane instruments: wide-band and narrow-band filtergraphs and
  a spectro-polarimeter for high spatial and temporal observations in
  the solar photospheric and chromospheric lines useful for sounding
  physical condition of dynamical phenomena.

Title: Chromospheric Lyman-alpha spectro-polarimeter (CLASP)
Authors: Kano, Ryouhei; Bando, Takamasa; Narukage, Noriyuki; Ishikawa,
   Ryoko; Tsuneta, Saku; Katsukawa, Yukio; Kubo, Masahito; Ishikawa,
   Shin-nosuke; Hara, Hirohisa; Shimizu, Toshifumi; Suematsu, Yoshinori;
   Ichimoto, Kiyoshi; Sakao, Taro; Goto, Motoshi; Kato, Yoshiaki; Imada,
   Shinsuke; Kobayashi, Ken; Holloway, Todd; Winebarger, Amy; Cirtain,
   Jonathan; De Pontieu, Bart; Casini, Roberto; Trujillo Bueno, Javier;
   Štepán, Jiří; Manso Sainz, Rafael; Belluzzi, Luca; Asensio Ramos,
   Andres; Auchère, Frédéric; Carlsson, Mats
Bibcode: 2012SPIE.8443E..4FK
Altcode:
  One of the biggest challenges in heliophysics is to decipher the
  magnetic structure of the solar chromosphere. The importance of
  measuring the chromospheric magnetic field is due to both the key role
  the chromosphere plays in energizing and structuring the outer solar
  atmosphere and the inability of extrapolation of photospheric fields to
  adequately describe this key boundary region. Over the last few years,
  significant progress has been made in the spectral line formation
  of UV lines as well as the MHD modeling of the solar atmosphere. It
  is found that the Hanle effect in the Lyman-alpha line (121.567 nm)
  is a most promising diagnostic tool for weaker magnetic fields in
  the chromosphere and transition region. Based on this groundbreaking
  research, we propose the Chromospheric Lyman-Alpha Spectro-Polarimeter
  (CLASP) to NASA as a sounding rocket experiment, for making the first
  measurement of the linear polarization produced by scattering processes
  and the Hanle effect in the Lyman-alpha line (121.567 nm), and making
  the first exploration of the magnetic field in the upper chromosphere
  and transition region of the Sun. The CLASP instrument consists
  of a Cassegrain telescope, a rotating 1/2-wave plate, a dual-beam
  spectrograph assembly with a grating working as a beam splitter, and
  an identical pair of reflective polarization analyzers each equipped
  with a CCD camera. We propose to launch CLASP in December 2014.

Title: The x-ray/EUV telescope for the Solar-C mission: science and
    development activities
Authors: Sakao, Taro; Narukage, Noriyuki; Imada, Shinsuke; Suematsu,
   Yoshinori; Shimojo, Masumi; Tsuneta, Saku; DeLuca, Edward E.; Watanabe,
   Kyoko; Ishikawa, Shin-nosuke
Bibcode: 2012SPIE.8443E..0AS
Altcode:
  We report science and development activities of the X-ray/EUV telescope
  for the Japanese Solar-C mission whose projected launch around 2019. The
  telescope consists of a package of (a) a normal-incidence (NI) EUV
  telescope and (b) a grazing-incidence (GI) soft X-ray telescope. The NI
  telescope chiefly provides images of low corona (whose temperature 1
  MK or even lower) with ultra-high angular resolution (0.2-0.3"/pixel)
  in 3 wavelength bands (304, 171, and 94 angstroms). On the other
  hand, the GI telescope provides images of the corona with a wide
  temperature coverage (1 MK to beyond 10 MK) with the highest-ever
  angular resolution (~0.5"/pixel) as a soft X-ray coronal imager. The
  set of NI and GI telescopes should provide crucial information for
  establishing magnetic and gas-dynamic connection between the corona and
  the lower atmosphere of the Sun which is essential for understanding
  heating of, and plasma activities in, the corona. Moreover, we attempt
  to implement photon-counting capability for the GI telescope with
  which imaging-spectroscopy of the X-ray corona will be performed for
  the first time, in the energy range from ~0.5 keV up to 10 keV. The
  imaging-spectroscopic observations will provide totally-new information
  on mechanism(s) for the generation of hot coronal plasmas (heated
  beyond a few MK), those for magnetic reconnection, and even generation
  of supra-thermal electrons associated with flares. An overview of
  instrument outline and science for the X-ray photoncounting telescope
  are presented, together with ongoing development activities in Japan
  towards soft X-ray photoncounting observations, focusing on high-speed
  X-ray CMOS detector and sub-arcsecond-resolution GI mirror.

Title: Excitation of Slow-Modes in Network Magnetic Elements
Authors: Kato, Y.; Steiner, O.; Steffen, M.; Suematsu, Y.
Bibcode: 2012ASPC..455..237K
Altcode:
  From radiation magnetohydrodynamic (RMHD) simulations of the solar
  atmosphere we have found a new mechanism for the excitation of
  longitudinal slow modes within magnetic flux concentrations. It is
  found that the convective downdrafts in the immediate surroundings of
  magnetic elements are responsible for the excitation of slow modes. The
  coupling between the external downdraft and the plasma motion internal
  to the flux concentration is mediated by the inertial forces of the
  downdraft that act on the magnetic flux concentration. These forces
  pump the internal atmosphere in the downward direction, which entails
  a fast downflow in the photospheric and chromospheric layers of the
  magnetic element. Subsequent to the transient pumping phase, the
  atmosphere rebounds, causing a slow mode traveling along the magnetic
  flux concentration in the upward direction and developing into a shock
  wave in chromospheric heights, possibly capable of producing some kind
  of dynamic fibril. This event occurs recurrently. We compare the power
  spectra of the temperature and velocity of the flux-sheet atmosphere
  to the corresponding spectra of the unmagnetized atmosphere.

Title: The Chromospheric Lyman-Alpha SpectroPolarimeter: CLASP
Authors: Kobayashi, K.; Kano, R.; Trujillo-Bueno, J.; Asensio Ramos,
   A.; Bando, T.; Belluzzi, L.; Carlsson, M.; De Pontieu, R. C. B.; Hara,
   H.; Ichimoto, K.; Ishikawa, R.; Katsukawa, Y.; Kubo, M.; Manso Sainz,
   R.; Narukage, N.; Sakao, T.; Stepan, J.; Suematsu, Y.; Tsuneta, S.;
   Watanabe, H.; Winebarger, A.
Bibcode: 2012ASPC..456..233K
Altcode:
  The magnetic field plays a crucial role in the chromosphere and the
  transition region, and our poor empirical knowledge of the magnetic
  field in the upper chromosphere and transition region is a major
  impediment to advancing the understanding of the solar atmosphere. The
  Hanle effect promises to be a valuable alternative to Zeeman effect
  as a method of measuring the magnetic field in the chromosphere and
  transition region; it is sensitive to weaker magnetic fields, and
  also sensitive to tangled, unresolved field structures. <P />CLASP
  is a sounding rocket experiment that aims to observe the Hanle effect
  polarization of the Lyman α (1215.67Å) line in the solar chromosphere
  and transition region, and prove the usefulness of this technique in
  placing constraints on the magnetic field strength and orientation
  in the low plasma-β region of the solar atmosphere. The Ly-α line
  has been chosen because it is a chromospheric/transition-region line,
  and because the Hanle effect polarization of this line is predicted to
  be sensitive to 10-250 Gauss, encompassing the range of interest. The
  CLASP instrument is designed to measure linear polarization in the
  Ly-α line with a polarization sensitivity of 0.1%. The instrument is
  currently funded for development. The optical design of the instrument
  has been finalized, and an extensive series of component-level tests
  are underway to validate the design.

Title: Precursor of Sunspot Penumbral Formation Discovered with
    Hinode SOT Observation
Authors: Shimizu, T.; Ichimoto, K.; Suematsu, Y.
Bibcode: 2012ASPC..456...43S
Altcode:
  We newly found a precursory signature of sunspot penumbral formation
  in Ca II H images. The precursor is a dark annular zone (width 3"-5")
  around the umbra (pore), which was formed soon after the pore formation
  and existed until the penumbral formation. The penumbra was developed
  as if to fill the annular zone. Pre-existing ambient magnetic field
  islands were moved to be distributed at the outer edge of the annular
  zone and did not come into the zone. The observations indicate that
  the annular zone is different from sunspot moat flow region and that
  the zone is visible only in chromospheric Ca II H images, not in
  photospheric G-band images. We conclude that the annular zone reflects
  the formation of a magnetic canopy overlying the region surrounding
  the umbra at the chromospheric level, much before the formation of the
  penumbra at the photospheric level. We can predict the region and size
  of the penumbra, by looking at the appearance of dark zone around pores.

Title: Precursor of Sunspot Penumbral Formation Discovered with
    Hinode Solar Optical Telescope Observations
Authors: Shimizu, Toshifumi; Ichimoto, Kiyoshi; Suematsu, Yoshinori
Bibcode: 2012ApJ...747L..18S
Altcode: 2012arXiv1202.1025S
  We present observations of a precursory signature that would be helpful
  for understanding the formation process of sunspot penumbrae. The Hinode
  Solar Optical Telescope successfully captured the entire evolution of a
  sunspot from the pore to a large well-developed sunspot with penumbra
  in an emerging flux region appearing in NOAA Active Region 11039. We
  found an annular zone (width 3''-5'') surrounding the umbra (pore)
  in Ca II H images before the penumbra formed around the umbra. The
  penumbra developed as if to fill the annular zone. The annular zone
  shows weak magnetogram signals, meaning less magnetic flux or highly
  inclined fields there. Pre-existing ambient magnetic field islands were
  distributed at the outer edge of the annular zone and did not come into
  the zone. There are no strong systematic flow patterns in the zone,
  but we occasionally observed small magnetic flux patches streaming
  out. The observations indicate that the annular zone is different from
  the sunspot moat flow region and that it represents the structure in the
  chromosphere. We conclude that the annular zone reflects the formation
  of a magnetic canopy overlying the region surrounding the umbra at the
  chromospheric level, long before the formation of the penumbra at the
  photospheric level. The magnetic field structure in the chromosphere
  needs to be considered in the formation process of the penumbrae.

Title: The Chromospheric Lyman-Alpha SpectroPolarimeter (CLASP)j
Authors: Kobayashi, K.; Tsuneta, S.; Trujillo Bueno, J.; Bando, T.;
   Belluzzi, L.; Casini, R.; Carlsson, M.; Cirtain, J. W.; De Pontieu,
   B.; Hara, H.; Ichimoto, K.; Ishikawa, R.; Kano, R.; Katsukawa, Y.;
   Kim, T.; Kubo, M.; Manso Sainz, R.; Narukage, N.; Asensio Ramos,
   A.; Robinson, B.; Sakao, T.; Shimizu, T.; Stepan, J.; Suematsu, Y.;
   Watanabe, H.; West, E.; Winebarger, A. R.
Bibcode: 2011AGUFM.P14C..05K
Altcode:
  We present an overview of the Chromospheric Lyman-Alpha
  SpectroPolarimeter (CLASP) program. CLASP is a proposed sounding rocket
  experiment currently under development as collaboration between Japan,
  USA and Spain. The aim is to achieve the first measurement of magnetic
  field in the upper chromosphere and transition region of the Sun
  through the detection and measurement of Hanle effect polarization
  of the Lyman alpha line. The Hanle effect (i.e. the magnetic field
  induced modification of the linear polarization due to scattering
  processes in spectral lines) is believed to be a powerful tool for
  measuring the magnetic field in the upper chromosphere, as it is more
  sensitive to weaker magnetic fields than the Zeeman effect, and also
  sensitive to magnetic fields tangled at spatial scales too small to be
  resolved. The Lyman-alpha (121.567 nm) line has been chosen because
  it is a chromospheric/transition-region line, and because the Hanle
  effect polarization of the Lyman-alpha line is predicted to be sensitive
  to 10-250 Gauss, encompassing the range of interest. Hanle effect is
  predicted to be observable as linear polarization or depolarization,
  depending on the geometry, with a fractional polarization amplitude
  varying between 0.1% and 1% depending on the strength and orientation of
  the magnetic field. This quantification of the chromospheric magnetic
  field requires a highly sensitive polarization measurement. The
  CLASP instrument consists of a large aperture (287 mm) Cassegrain
  telescope mated to a polarizing beamsplitter and a matched pair
  of grating spectrographs. The polarizing beamsplitter consists
  of a continuously rotating waveplate and a linear beamsplitter,
  allowing simultaneous measurement of orthogonal polarizations and
  in-flight self-calibration. Development of the instrument is underway,
  and prototypes of all optical components have been tested using a
  synchrotron beamline. The experiment is proposed for flight in 2014.

Title: Integral Field Spectroscopy of the Sun with Microlens Array
    and Liquid Crystal Retarders
Authors: Suematsu, Y.; Shinoda, K.; Sano, I.; Kobiki, T.
Bibcode: 2011AGUFMSH13B1947S
Altcode:
  Simultaneous spectrographic observations over extended solar structures,
  at a high spatial resolution and temporal cadence, are important
  to track and understand the physics of transient phenomena such as
  Ellerman bombs, flare kernels, prominences/filaments and spicules. With
  two-dimensional (2-D) field spectral data, we can make monochromatic
  images at a given wavelength in a designed passband and line profile
  analysis to derive 2-D distribution of atmospheric parameters. One
  technique to produce a spectrum of each spatial elements in an extended
  two-dimensional field is to use a micro-lens array. Replacing a slit
  of a conventional spectrograph with a micro-lens array then helps to
  capture two-dimensionally distributed short spectra from 2-D field
  using additional optics inserted, a bandpass filter and a large format
  detector. For observations of magnetic field, we can add polarization
  modulator made of liquid crystal retarders which give a sequence of
  alternative orthogonal polarization states with time. We describe a
  design concept and limitations for observations with the micro-lens
  array spectrograph and an initial result applied for a few existing
  solar telescopes at NAOJ and Hida Observatory, Kyoto University.

Title: Focal plane instrument for the Solar UV-Vis-IR Telescope
    aboard SOLAR-C
Authors: Katsukawa, Yukio; Suematsu, Yoshinori; Shimizu, Toshifumi;
   Ichimoto, Kiyoshi; Takeyama, Norihide
Bibcode: 2011SPIE.8148E..0EK
Altcode: 2011SPIE.8148E..13K
  It is presented the conceptual design of a focal plane instrument for
  the Solar UV-Vis-IR Telescope (SUVIT) aboard the next Japanese solar
  mission SOLAR-C. A primary purpose of the telescope is to achieve
  precise as well as high resolution spectroscopic and polarimetric
  measurements of the solar chromosphere with a big aperture of 1.5 m,
  which is expected to make a significant progress in understanding basic
  MHD processes in the solar atmosphere. The focal plane instrument
  consists of two packages: A filtergraph package is to get not only
  monochromatic images but also Dopplergrams and magnetograms using a
  tunable narrow-band filter and interference filters. A spectrograph
  package is to perform accurate spectro-polarimetric observations for
  measuring chromospheric magnetic fields, and is employing a Littrow-type
  spectrograph. The most challenging aspect in the instrument design is
  wide wavelength coverage from 280 nm to 1.1 μm to observe multiple
  chromospheric lines, which is to be realized with a lens unit including
  fluoride glasses. A high-speed camera for correlation tracking of
  granular motion is also implemented in one of the packages for an
  image stabilization system, which is essential to achieve high spatial
  resolution and high polarimetric accuracy.

Title: Photon-counting soft x-ray telescope for the Solar-C mission
Authors: Sakao, Taro; Narukage, Noriyuki; Shimojo, Masumi; Tsuneta,
   Saku; Suematsu, Yoshinori; Miyazaki, Satoshi; Imada, Shinsuke;
   Nishizuka, Naoto; Watanabe, Kyoko; Dotani, Tadayasu; DeLuca, Edward
   E.; Ishikawa, Shin-nosuke
Bibcode: 2011SPIE.8148E..0CS
Altcode: 2011SPIE.8148E..11S
  We report instrument outline as well as science of the photon-counting
  soft X-ray telescope that we have been studying as a possible scientific
  payload for the Japanese Solar-C mission whose projected launch around
  2019. Soft X-rays (~1- 10 keV) from the solar corona include rich
  information on (1) possible mechanism(s) for heating the bright core of
  active regions seen in soft X-rays (namely, the hottest portion in the
  non-flaring corona), (2) dynamics and magnetohydrodynamic structures
  associated with magnetic reconnection processes ongoing in flares,
  and even (3) generation of supra-thermal distributions of coronal
  plasmas associated with flares. Nevertheless, imaging-spectroscopic
  investigation of the soft X-ray corona has so far remained unexplored
  due to difficulty in the instrumentation for achieving this aim. With
  the advent of recent remarkable progress in CMOS-APS detector
  technology, the photon-counting X-ray telescope will be capable
  of, in addition to conventional photon-integration type exposures,
  performing imaging-spectroscopic investigation on active regions and
  flares, thus providing, for example, detailed temperature information
  (beyond the sofar- utilized filter-ratio temperature) at each spatial
  point of the observing target. The photon-counting X-ray telescope will
  emply a Wolter type I optics with a piece of a segmented mirror whose
  focal length 4 meters, combined with a focal-plane CMOS-APS detector
  (0.4-0.5"/pixel) whose frame read-out rate required to be as high as
  1000 fps.

Title: Overview of Chromospheric Lyman-Alpha SpectroPolarimeter
    (CLASP)
Authors: Narukage, Noriyuki; Tsuneta, Saku; Bando, Takamasa; Kano,
   Ryouhei; Kubo, Masahito; Ishikawa, Ryoko; Hara, Hirohisa; Suematsu,
   Yoshinori; Katsukawa, Yukio; Watanabe, Hiroko; Ichimoto, Kiyoshi;
   Sakao, Taro; Shimizu, Toshifumi; Kobayashi, Ken; Robinson, Brian; Kim,
   Tony; Winebarger, Amy; West, Edward; Cirtain, Jonathan; De Pontieu,
   Bart; Casini, Roberto; Trujillo Bueno, Javier; Stepan, Jiri; Manso
   Sainz, Rafael; Belluzzi, Luca; Asensio Ramos, Andres; Carlsson, Mats
Bibcode: 2011SPIE.8148E..0HN
Altcode: 2011SPIE.8148E..16N
  The solar chromosphere is an important boundary, through which all of
  the plasma, magnetic fields and energy in the corona and solar wind
  are supplied. Since the Zeeman splitting is typically smaller than
  the Doppler line broadening in the chromosphere and transition region,
  it is not effective to explore weak magnetic fields. However, this is
  not the case for the Hanle effect, when we have an instrument with
  high polarization sensitivity (~ 0.1%). "Chromospheric Lyman- Alpha
  SpectroPolarimeter (CLASP)" is the sounding rocket experiment to detect
  linear polarization produced by the Hanle effect in Lyman-alpha line
  (121.567 nm) and to make the first direct measurement of magnetic
  fields in the upper chromosphere and lower transition region. To
  achieve the high sensitivity of ~ 0.1% within a rocket flight (5
  minutes) in Lyman-alpha line, which is easily absorbed by materials,
  we design the optical system mainly with reflections. The CLASP
  consists of a classical Cassegrain telescope, a polarimeter and a
  spectrometer. The polarimeter consists of a rotating 1/2-wave plate
  and two reflecting polarization analyzers. One of the analyzer also
  works as a polarization beam splitter to give us two orthogonal linear
  polarizations simultaneously. The CLASP is planned to be launched in
  2014 summer.

Title: The SOLAR-C mission: current status
Authors: Shimizu, Toshifumi; Tsuneta, Saku; Hara, Hirohisa; Ichimoto,
   Kiyoshi; Kusano, Kanya; Sakao, Taro; Sekii, Takashi; Suematsu,
   Yoshinori; Watanabe, Tetsuya
Bibcode: 2011SPIE.8148E..0BS
Altcode: 2011SPIE.8148E..10S
  Two mission concepts (plan A: out-of-ecliptic mission and plan B:
  high resolution spectroscopic mission) have been studied for the next
  Japanese-led solar mission Solar-C, which will follow the scientific
  success of the Hinode mission. The both mission concepts are concluded
  as equally important and attractive for the promotion of space solar
  physics. In the meantime we also had to make efforts for prioritizing
  the two options, in order to proceed to next stage of requesting the
  launch of Solar-C mission at the earliest opportunity. This paper
  briefly describes the two mission concepts and the current status
  on our efforts for prioritizing the two options. More details are
  also described for the plan B option as the first-priority Solar-C
  mission. The latest report from the Solar-C mission concept studies
  was documented as "Interim Report on the Solar-C Mission Concept."

Title: Short telescope design of 1.5-m aperture solar UV visible
    and IR telescope aboard Solar-C
Authors: Suematsu, Y.; Katsukawa, Y.; Shimizu, T.; Ichimoto, K.;
   Horiuchi, T.; Matsumoto, Y.; Takeyama, N.
Bibcode: 2011SPIE.8148E..0DS
Altcode: 2011SPIE.8148E..12S
  We present an optical and thermal design of one of major instrumental
  payload planned for SOLAR-C mission/Plan-B (high resolution
  spectroscopic option): the telescope assembly of Solar Ultra-violet
  Visible and near IR observing Telescope (SUVIT). To accommodate a
  launcher's nosecone size, a wide observing wavelength coverage from UV
  (down to 280 nm) through near IR (up to 1100 nm), and an 0.1 arcsec
  resolution in the field of 200 arcsec diameter, a short telescope
  design was made for a 1.5 m aperture solar Gregorian telescope with
  the compact design of three-mirror collimator unit.

Title: Modeling and verification of the diffraction-limited visible
    light telescope aboard the solar observing satellite HINODE
Authors: Katsukawa, Y.; Suematsu, Y.; Tsuneta, S.; Ichimoto, K.;
   Shimizu, T.
Bibcode: 2011SPIE.8336E..0FK
Altcode: 2011SPIE.8336E..14K
  HINODE, Japanese for "sunrise", is a spacecraft dedicated for
  observations of the Sun, and was launched in 2006 to study the Sun's
  magnetic fields and how their explosive energies propagate through the
  different atmospheric layers. The spacecraft carries the Solar Optical
  Telescope (SOT), which has a 50 cm diameter clear aperture and provides
  a continuous series of diffraction-limited visible light images from
  space. The telescope was developed through international collaboration
  between Japan and US. In order to achieve the diffraction-limited
  performance, thermal and structural modeling of the telescope was
  extensively used in its development phase to predict how the optical
  performance changes dependent on the thermal condition in orbit. Not
  only the modeling, we devoted many efforts to verify the optical
  performance in ground tests before the launch. The verification in
  the ground tests helped us to find many issues, such as temperature
  dependent focus shifts, which were not identified only through the
  thermal-structural modeling. Another critical issue was micro-vibrations
  induced by internal disturbances of mechanical gyroscopes and momentum
  wheels for attitude control of the spacecraft. Because the structural
  modeling was not accurate enough to predict how much the image quality
  was degraded by the micro-vibrations, we measured their transmission
  in a spacecraft-level test.

Title: Excitation of magneto-acoustic waves in network magnetic
    elements
Authors: Kato, Yoshiaki; Steiner, Oskar; Steffen, Matthias; Suematsu,
   Yoshinori
Bibcode: 2011IAUS..273..442K
Altcode:
  From radiation magnetohydrodynamic (RMHD) simulations we track the
  temporal evolution of a vertical magnetic flux sheet embedded in a
  two-dimensional non-stationary atmosphere that reaches all the way
  from the upper convection zone to the low chromosphere. Examining its
  temporal behavior near the interface between the convection zone and
  the photosphere, we describe the excitation of propagating longitudinal
  waves within the magnetic element as a result of convective motion in
  its surroundings.

Title: Excitation of Slow Modes in Network Magnetic Elements Through
    Magnetic Pumping
Authors: Kato, Yoshiaki; Steiner, Oskar; Steffen, Matthias; Suematsu,
   Yoshinori
Bibcode: 2011ApJ...730L..24K
Altcode: 2011arXiv1102.5164K
  From radiation magnetohydrodynamic simulations of the solar atmosphere,
  we find a new mechanism for the excitation of longitudinal slow modes
  within magnetic flux concentrations. We find that the convective
  downdrafts in the immediate surroundings of magnetic elements are
  responsible for the excitation of slow modes. The coupling between
  the external downdraft and the plasma motion internal to the flux
  concentration is mediated by the inertial forces of the downdraft that
  act on the magnetic flux concentration. These forces, in conjunction
  with the downward movement, pump the internal atmosphere in the
  downward direction, which entails a fast downdraft in the photospheric
  and chromospheric layers of the magnetic element. Subsequent to the
  transient pumping phase, the atmosphere rebounds, causing a slow
  mode traveling along the magnetic flux concentration in the upward
  direction. It develops into a shock wave in chromospheric heights,
  possibly capable of producing some kind of dynamic fibril. We propose
  an observational detection of this process.

Title: Sunspot Proper Motion and Flare Onset Prediction
Authors: Suematsu, Y.; Yatini, C. Y.
Bibcode: 2010AGUFMSH43B1819S
Altcode:
  Proper motion of sunspots in several active regions was studied to
  detect their indicator on flare onset, using data from the Solar Flare
  Telescope at Mitaka, TRACE and Hinode. The proper motion of individual
  sunspots was derived using a local correlation tracking method. As
  a result, we found that the sunspots that are located under or close
  to H-alpha flaring patches showed a change in their moving direction
  prior to the flare onset. The change in their movements took place a
  half to two hours before the flare onset. On the other hand, sunspots
  in non-flaring areas or non-flaring active regions did not show this
  kind of change. It is likely, therefore, that if a sunspot shows
  the particular movement, a H-alpha flare is to occur in its nearby
  region. In two of the active regions, the flare ribbons were located
  on a emerging bipolar pair of sunspots. The disturbance in the usual
  motion of the bipolar sunspots and in other sunspots as well can be
  interpreted as a sign of magnetic shear development leading to final
  magnetic energy buildup before its sudden release. We suggest that
  the change in sunspot motion in a short time scale prior to the flare
  onset can be regarded as a good indicator in predicting the onset
  timing and location of H-alpha flare.

Title: Quiescent Prominence Dynamics Observed with the Hinode Solar
    Optical Telescope. I. Turbulent Upflow Plumes
Authors: Berger, Thomas E.; Slater, Gregory; Hurlburt, Neal; Shine,
   Richard; Tarbell, Theodore; Title, Alan; Lites, Bruce W.; Okamoto,
   Takenori J.; Ichimoto, Kiyoshi; Katsukawa, Yukio; Magara, Tetsuya;
   Suematsu, Yoshinori; Shimizu, Toshifumi
Bibcode: 2010ApJ...716.1288B
Altcode:
  Hinode/Solar Optical Telescope (SOT) observations reveal two new
  dynamic modes in quiescent solar prominences: large-scale (20-50 Mm)
  "arches" or "bubbles" that "inflate" from below into prominences, and
  smaller-scale (2-6 Mm) dark turbulent upflows. These novel dynamics are
  related in that they are always dark in visible-light spectral bands,
  they rise through the bright prominence emission with approximately
  constant speeds, and the small-scale upflows are sometimes observed to
  emanate from the top of the larger bubbles. Here we present detailed
  kinematic measurements of the small-scale turbulent upflows seen in
  several prominences in the SOT database. The dark upflows typically
  initiate vertically from 5 to 10 Mm wide dark cavities between the
  bottom of the prominence and the top of the chromospheric spicule
  layer. Small perturbations on the order of 1 Mm or less in size
  grow on the upper boundaries of cavities to generate plumes up to
  4-6 Mm across at their largest widths. All plumes develop highly
  turbulent profiles, including occasional Kelvin-Helmholtz vortex
  "roll-up" of the leading edge. The flows typically rise 10-15 Mm before
  decelerating to equilibrium. We measure the flowfield characteristics
  with a manual tracing method and with the Nonlinear Affine Velocity
  Estimator (NAVE) "optical flow" code to derive velocity, acceleration,
  lifetime, and height data for several representative plumes. Maximum
  initial speeds are in the range of 20-30 km s<SUP>-1</SUP>, which
  is supersonic for a ~10,000 K plasma. The plumes decelerate in the
  final few Mm of their trajectories resulting in mean ascent speeds
  of 13-17 km s<SUP>-1</SUP>. Typical lifetimes range from 300 to 1000
  s (~5-15 minutes). The area growth rate of the plumes (observed as
  two-dimensional objects in the plane of the sky) is initially linear
  and ranges from 20,000 to 30,000 km<SUP>2</SUP> s<SUP>-1</SUP> reaching
  maximum projected areas from 2 to 15 Mm<SUP>2</SUP>. Maximum contrast of
  the dark flows relative to the bright prominence plasma in SOT images
  is negative and ranges from -10% for smaller flows to -50% for larger
  flows. Passive scalar "cork movies" derived from NAVE measurements show
  that prominence plasma is entrained by the upflows, helping to counter
  the ubiquitous downflow streams in the prominence. Plume formation
  shows no clear temporal periodicity. However, it is common to find
  "active cavities" beneath prominences that can spawn many upflows in
  succession before going dormant. The mean flow recurrence time in these
  active locations is roughly 300-500 s (5-8 minutes). Locations remain
  active on timescales of tens of minutes up to several hours. Using a
  column density ratio measurement and reasonable assumptions on plume
  and prominence geometries, we estimate that the mass density in the
  dark cavities is at most 20% of the visible prominence density, implying
  that a single large plume could supply up to 1% of the mass of a typical
  quiescent prominence. We hypothesize that the plumes are generated from
  a Rayleigh-Taylor instability taking place on the boundary between
  the buoyant cavities and the overlying prominence. Characteristics,
  such as plume size and frequency, may be modulated by the strength
  and direction of the cavity magnetic field relative to the prominence
  magnetic field. We conclude that buoyant plumes are a source of
  quiescent prominence mass as well as a mechanism by which prominence
  plasma is advected upward, countering constant gravitational drainage.

Title: Review of Hinode results
Authors: Suematsu, Y.
Bibcode: 2010AN....331..605S
Altcode:
  Hinode is an observatory-style satellite, carrying three advanced
  instruments being designed and built to work together to explore
  the physical coupling between the photosphere and the upper layers
  for understanding the mechanism of dynamics and heating. The three
  instruments aboard are the Solar Optical Telescope (SOT), which
  can provide high-precision photometric and polarimetric data of the
  lower atmosphere in the visible light (388-668 nm) with a spatial
  resolution of 0.2-0.3 arcseconds, the X-Ray Telescope (XRT) which
  takes a wide field of full sun coverage X-ray images being capable
  of diagnosing the physical condition of coronal plasmas, and the EUV
  Imaging Spectrometer (EIS) which observes the upper transition region
  and coronal emission lines in the wavelength ranges of 17-21 nm and
  25-29 nm. Since first-light observations in the end of October 2006,
  Hinode has been continuously providing unprecedented high-quality
  solar data. We will present some new findings of the sun with Hinode,
  focusing on those from SOT.

Title: On the evaluation of image quality of Hinode Solar Optical
    Telescope
Authors: Suematsu, Y.
Bibcode: 2009AGUFMSH51A1254S
Altcode:
  The phase diversity method is a useful tool to estimate a
  wavefront error of a whole optical system from an object through a
  detector. Generally, in this method, both on-focus and out of focus
  images are taken simultaneously by splitting a beam just before the
  final focal plane. From a pair of these two images and known de-focus
  value, a wavefront error at a pupil which is assumed to be represented
  a series of the circle polynomials are derived so as to minimize the
  difference of observed images from the disturbed by the wavefront. In
  case of the Solar Optical Telescope (SOT), on-focus and out of focus
  images are taken sequentially by moving a focusing lens. Therefore, the
  sequence of images may have other aberration than the defocus because of
  an introduced wavefront error of the moving focusing lens. We describe
  a modified phase diversity method which can be applied to the SOT. The
  obtained results, which are useful to improve the image quality,
  are discussed by comparing the case of standard phase diversity method.

Title: A New View of Fine Scale Dynamics and Magnetism of Sunspots
    Revealed by Hinode/SOT
Authors: Ichimoto, K.; Suematsu, Y.; Katsukawa, Y.; Tsuneta, S.;
   Shimojo, M.; Shimizu, T.; Shine, R. A.; Tarbell, T. D.; Berger, T.;
   Title, A. M.; Lites, B. W.; Kubo, M.; Yokoyama, T.; Nagata, S.
Bibcode: 2009ASPC..405..167I
Altcode:
  The Solar Optical Telescope on-board Hinode is providing a new view of
  the fine scale dynamics in sunspots with its high spatial resolution and
  unprecedented image stability. We present three features related to the
  Evershed flow each of which raises a new puzzle in sunspot dynamics;
  i.e., twisting appearance of penumbral filaments, the source and sink
  of individual Evershed flow channels, and the net circular polarization
  in penumbrae with its spatial relation to the Evershed flow channels.

Title: Local Twist and Current Helicity Distributions of Active
    Region NOAA 10930
Authors: Su, J. T.; Sakurai, T.; Suematsu, Y.; Hagino, M.; Liu, Yu
Bibcode: 2009ApJ...697L.103S
Altcode:
  Hinode high-quality vector magnetograms and G-band data are utilized
  to study the distributions of local twist α<SUB> z </SUB> and current
  helicity h<SUB>c</SUB> on the active region of NOAA 10930. The new
  findings are as follows. (1) The patches of positive and negative
  helicities were intermixed showing a mesh pattern in the umbra and
  a thread pattern in the penumbra. (2) For its main stable sunspot
  (MSS), there was a positive-helicity patch accounting for ~43% of the
  umbra area surrounding the inner umbra, which had a predominantly
  negative helicity. For its minor rotating sunspot (MRS), there
  was a negative-helicity patch appearing in the umbra. (3) The fine
  distributions of α<SUB> z </SUB> and h<SUB>c</SUB> on a penumbral
  filament indicated that it may be possible for the two opposite
  helicities to coexist in a filament and their magnitudes were nearly
  equivalent.

Title: Has Hinode Revealed the Missing Turbulent Flux of the
    Quiet Sun?
Authors: Lites, B. W.; Kubo, M.; Socas-Navarro, H.; Berger, T.; Frank,
   Z.; Shine, R.; Tarbell, T.; Title, A. M.; Ichimoto, K.; Katsukawa,
   Y.; Tsuneta, S.; Suematsu, Y.; Shimizu, T.; Nagata, S.
Bibcode: 2009ASPC..405..173L
Altcode:
  The Hinode Spectro-Polarimeter has revealed the presence of surprisingly
  strong horizontal magnetic fields nearly everywhere in the quiet
  solar atmosphere. These horizontal fields, along with measures of the
  vertical fields, may be the signature of the ``hidden turbulent flux''
  of the quiet Sun. The measured horizontal fields average at least to
  55 Gauss: nearly 5 times that of the measured longitudinal apparent
  flux density. The nature of these fields are reviewed, and discussed
  in the light of recent magneto-convection numerical simulations of
  the quiet Sun.

Title: Hinode Observation of the Magnetic Fields in a Sunspot Light
    Bridge Accompanied by Long-Lasting Chromospheric Plasma Ejections
Authors: Shimizu, Toshifumi; Katsukawa, Yukio; Kubo, Masahito; Lites,
   Bruce W.; Ichimoto, Kiyoshi; Suematsu, Yoshinori; Tsuneta, Saku;
   Nagata, Shin'ichi; Shine, Richard A.; Tarbell, Theodore D.
Bibcode: 2009ApJ...696L..66S
Altcode:
  We present high-resolution magnetic field measurements of a sunspot
  light bridge (LB) that produced chromospheric plasma ejections
  intermittently and recurrently for more than 1 day. The observations
  were carried out with the Hinode Solar Optical Telescope on 2007
  April 29 and 30. The spectro-polarimeter reveals obliquely oriented
  magnetic fields with vertical electric current density higher than
  100 mA m<SUP>-2</SUP> along the LB. The observations suggest that
  current-carrying highly twisted magnetic flux tubes are trapped below
  a cusp-shaped magnetic structure along the LB. The presence of trapped
  current-carrying flux tubes is essential for causing long-lasting
  chromospheric plasma ejections at the interface with pre-existing
  vertically oriented umbral fields. A bidirectional jet was clearly
  detected, suggesting magnetic reconnections occurring at very low
  altitudes, slightly above the height where the vector magnetic fields
  are measured. Moreover, we found another strong vertical electric
  current on the interface between the current-carrying flux tube
  and pre-existing umbral field, which might be a direct detection
  of the currents flowing in the current sheet formed at the magnetic
  reconnection sites.

Title: Prominence Formation Associated with an Emerging Helical
    Flux Rope
Authors: Okamoto, Takenori J.; Tsuneta, Saku; Lites, Bruce W.; Kubo,
   Masahito; Yokoyama, Takaaki; Berger, Thomas E.; Ichimoto, Kiyoshi;
   Katsukawa, Yukio; Nagata, Shin'ichi; Shibata, Kazunari; Shimizu,
   Toshifumi; Shine, Richard A.; Suematsu, Yoshinori; Tarbell, Theodore
   D.; Title, Alan M.
Bibcode: 2009ApJ...697..913O
Altcode: 2009arXiv0904.0007O
  The formation and evolution process and magnetic configuration of
  solar prominences remain unclear. In order to study the formation
  process of prominences, we examine continuous observations of a
  prominence in NOAA AR 10953 with the Solar Optical Telescope on
  the Hinode satellite. As reported in our previous Letter, we find
  a signature suggesting that a helical flux rope emerges from below
  the photosphere under a pre-existing prominence. Here we investigate
  more detailed properties and photospheric indications of the emerging
  helical flux rope, and discuss their relationship to the formation of
  the prominence. Our main conclusions are: (1) a dark region with absence
  of strong vertical magnetic fields broadens and then narrows in Ca II
  H-line filtergrams. This phenomenon is consistent with the emergence
  of the helical flux rope as photospheric counterparts. The size of the
  flux rope is roughly 30,000 km long and 10,000 km wide. The width is
  larger than that of the prominence. (2) No shear motion or converging
  flows are detected, but we find diverging flows such as mesogranules
  along the polarity inversion line. The presence of mesogranules may
  be related to the emergence of the helical flux rope. (3) The emerging
  helical flux rope reconnects with magnetic fields of the pre-existing
  prominence to stabilize the prominence for the next several days. We
  thus conjecture that prominence coronal magnetic fields emerge in
  the form of helical flux ropes that contribute to the formation and
  maintenance of the prominence.

Title: The Magnetic Landscape of the Sun's Polar Region
Authors: Tsuneta, S.; Ichimoto, K.; Katsukawa, Y.; Lites, B. W.;
   Matsuzaki, K.; Nagata, S.; Orozco Suárez, D.; Shimizu, T.; Shimojo,
   M.; Shine, R. A.; Suematsu, Y.; Suzuki, T. K.; Tarbell, T. D.; Title,
   A. M.
Bibcode: 2008ApJ...688.1374T
Altcode: 2008arXiv0807.4631T
  We present observations of the magnetic landscape of the polar region
  of the Sun that are unprecedented in terms of spatial resolution,
  field of view, and polarimetric precision. They were carried out with
  the Solar Optical Telescope aboard Hinode. Using a Milne-Eddington
  inversion, we find many vertically oriented magnetic flux tubes
  with field strengths as strong as 1 kG scattered in latitude between
  70° and 90°. They all have the same polarity, consistent with the
  global polarity of the polar region. The field vectors are observed to
  diverge from the centers of the flux elements, consistent with a view
  of magnetic fields that are expanding and fanning out with height. The
  polar region is also found to have ubiquitous horizontal fields. The
  polar regions are the source of the fast solar wind, which is channeled
  along unipolar coronal magnetic fields whose photospheric source is
  evidently rooted in the strong-field, vertical patches of flux. We
  conjecture that vertical flux tubes with large expansion around the
  photospheric-coronal boundary serve as efficient chimneys for Alfvén
  waves that accelerate the solar wind.

Title: Estimation of Spicule Magnetic Field Using Observed MHD Waves
    by the Hinode SOT
Authors: Kim, Yeon-Han; Bong, Su-Chan; Park, Young-Deuk; Cho,
   Kyung-Suk; Moon, Yong-Jae; Suematsu, Yoshinori
Bibcode: 2008JKAS...41..173K
Altcode:
  No abstract at ADS

Title: Nature of Small-Scale Jets On the Solar Chromosphere Revealed
    with Hinode
Authors: Suematsu, Y.
Bibcode: 2008AGUFMSH41B1623S
Altcode:
  The Solar Optical Telescope aboard Hinode has revealed the nature of
  small-scale jets of the solar chromosphere. Jet-like structures are
  ubiquitous there not only in the quiet Sun but also in active region
  and even in sunspot penumbra. They are likely to play an important role
  in maintaining the energy balance of the local atomsphere and the mass
  balance of the corona. High time and spatial resolution observations
  for the first time have revealed that the small-scale jets consist of
  highly dynamic multi-threads of as thin as a few tenths of arcsecond
  and shows prominent lateral movement or oscillation with rotation
  on its axis during its life. The fine structure and lateral motion
  indicate that the small-scale can be ejected by magnetic reconnection
  at footpoints. Since the most small-scale jets emanate from seemingly
  uni-polar magnetic region and the relevant magnetic reconnection should
  take place in unresolved spatial scale contrary to the larger-scale jets
  in which bipole magnetic structures are found at their footpoints. We
  discuss multi-scale structures of the chromospheric jets.

Title: Magnetic Fields of the Quiet Sun: A New Quantitative
    Perspective From Hinode
Authors: Lites, B. W.; Kubo, M.; Socas-Navarro, H.; Berger, T.; Frank,
   Z.; Shine, R.; Tarbell, T.; Title, A.; Ichimoto, K.; Katsukawa, Y.;
   Tsuneta, S.; Suematsu, Y.; Shimizu, T.; Nagata, S.
Bibcode: 2008ASPC..397...17L
Altcode:
  This article summarizes results of studies presented in two papers
  already published: Lites et al. (2007a); Lites et al. (2007b). Please
  see these for further details.

Title: On-orbit Performance of the Solar Optical Telescope aboard
    Hinode
Authors: Ichimoto, K.; Katsukawa, Y.; Tarbell, T.; Shine, R. A.;
   Hoffmann, C.; Berger, T.; Cruz, T.; Suematsu, Y.; Tsuneta, S.; Shimizu,
   T.; Lites, B. W.
Bibcode: 2008ASPC..397....5I
Altcode: 2008arXiv0804.3248I
  On-orbit performance of the Solar Optical Telescope (SOT) aboard Hinode
  is described with some attention to its unpredicted aspects. In general,
  SOT reveals an excellent performance and has been providing outstanding
  data. Some unexpected features exist, however, in behaviours of the
  focus position, throughput and structural stability. Most of them are
  recovered by the daily operation i.e., frequent focus adjustment,
  careful heater setting and corrections in data analysis. The
  tunable filter contains air bubbles which degrade the data quality
  significantly. Schemes for tuning the filter without disturbing the
  bubbles have been developed and tested, and some useful procedures
  to obtain Dopplergrams and magnetograms are now available. October
  and March, when the orbit of satellite becomes nearly perpendicular
  to the direction towards the Sun, provide a favourable condition for
  continuous runs of the narrow-band filter imager.

Title: High Resolution Observations of Spicules with Hinode/SOT
Authors: Suematsu, Y.; Ichimoto, K.; Katsukawa, Y.; Shimizu, T.;
   Okamoto, T.; Tsuneta, S.; Tarbell, T.; Shine, R. A.
Bibcode: 2008ASPC..397...27S
Altcode:
  High time cadence unprecedented images at the limb with Ca II H line
  filtergraph from the Solar Optical Telescope (SOT) aboard Hinode
  have revealed that a spicule consists of highly dynamic multi-threads
  (typically twin) as thin as a few tenths of an arcsecond, and shows
  prominent lateral movement or oscillation with rotation on its axis
  during its life. This multi-thread structure and lateral motion indicate
  that the spicules can be driven by magnetic reconnection at unresolved
  spatial scales at their footpoints.

Title: Evolution of Magnetic Fields at the Boundary of the Penumbra
Authors: Kubo, M.; Ichimoto, K.; Shimizu, T.; Lites, B. W.; Tsuneta,
   S.; Suematsu, Y.; Katsukawa, Y.; Nagata, S.; Tarbell, T.; Shine,
   R. A.; Title, A. M.
Bibcode: 2008ASPC..397...79K
Altcode:
  The formation of moving magnetic features (MMFs) separating from the
  penumbra were successfully observed with the Solar Optical Telescope
  (SOT) aboard the Hinode satellite. We find that bright features in
  the outer penumbra are located at the penumbral spines, which have
  magnetic fields more vertical than the surroundings, or located at the
  MMFs separating from the spines. This suggests that convection in the
  outer penumbra is related to the disintegration of the sunspot.

Title: Erratum: The Analysis of Penumbral Fine Structure Using an
    Advanced Inversion Technique
Authors: Jurcák, Jan; Bellot Rubio, Luis; Ichimoto, Kiyoshi;
   Katsukawa, Yukio; Lites, Bruce; Nagata, Shin'ichi; Shimizu, Toshifumi;
   Suematsu, Yoshinori; Tarbell, Theodore D.; Title, Alan M.; Tsuneta,
   Saku
Bibcode: 2008PASJ...60..933J
Altcode:
  In the article [PASJ 59, S601-S606 (2007)], the word ''CSIC'' was
  omitted from the affiliation of Dr. Luis Bellot Rubio. The correct
  affiliation is : <SUP>2</SUP>Instituto de Astrofísica de Andalucía
  (CSIC), Apdo. de Correos 3004, 18080 Granada, Spain

Title: Disintegration of Magnetic Flux in Decaying Sunspots as
    Observed with the Hinode SOT
Authors: Kubo, M.; Lites, B. W.; Ichimoto, K.; Shimizu, T.; Suematsu,
   Y.; Katsukawa, Y.; Tarbell, T. D.; Shine, R. A.; Title, A. M.; Nagata,
   S.; Tsuneta, S.
Bibcode: 2008ApJ...681.1677K
Altcode: 2008arXiv0806.0415K
  Continuous observations of sunspot penumbrae with the Solar Optical
  Telescope aboard Hinode clearly show that the outer boundary of the
  penumbra fluctuates around its averaged position. The penumbral outer
  boundary moves inward when granules appear in the outer penumbra. We
  discover that such granules appear one after another while moving
  magnetic features (MMFs) are separating from the penumbral "spines"
  (penumbral features that have fields that are stronger and more vertical
  than those of their surroundings). These granules that appear in the
  outer penumbra often merge with bright features inside the penumbra
  that move with the spines as they elongate toward the moat region. This
  suggests that convective motions around the penumbral outer boundary are
  related to the disintegration of magnetic flux in the sunspot. We also
  find that dark penumbral filaments frequently elongate into the moat
  region in the vicinity of MMFs that detach from penumbral spines. Such
  elongating dark penumbral filaments correspond to nearly horizontal
  fields extending from the penumbra. Pairs of MMFs with positive and
  negative polarities are sometimes observed along the elongating dark
  penumbral filaments. This strongly supports the notion that such
  elongating dark penumbral filaments have magnetic fields with a "sea
  serpent"-like structure. Evershed flows, which are associated with the
  penumbral horizontal fields, may be related to the detachment of the
  MMFs from the penumbral spines, as well as to the formation of the MMFs
  along the dark penumbral filaments that elongate into the moat region.

Title: Polarization Calibration of the Solar Optical Telescope
    onboard Hinode
Authors: Ichimoto, K.; Lites, B.; Elmore, D.; Suematsu, Y.; Tsuneta,
   S.; Katsukawa, Y.; Shimizu, T.; Shine, R.; Tarbell, T.; Title, A.;
   Kiyohara, J.; Shinoda, K.; Card, G.; Lecinski, A.; Streander, K.;
   Nakagiri, M.; Miyashita, M.; Noguchi, M.; Hoffmann, C.; Cruz, T.
Bibcode: 2008SoPh..249..233I
Altcode: 2008SoPh..tmp...69I
  The Solar Optical Telescope (SOT) onboard Hinode aims to obtain vector
  magnetic fields on the Sun through precise spectropolarimetry of
  solar spectral lines with a spatial resolution of 0.2 - 0.3 arcsec. A
  photometric accuracy of 10<SUP>−3</SUP> is achieved and, after the
  polarization calibration, any artificial polarization from crosstalk
  among Stokes parameters is required to be suppressed below the level
  of the statistical noise over the SOT's field of view. This goal was
  achieved by the highly optimized design of the SOT as a polarimeter,
  extensive analyses and testing of optical elements, and an end-to-end
  calibration test of the entire system. In this paper we review both
  the approach adopted to realize the high-precision polarimeter of the
  SOT and its final polarization characteristics.

Title: Image Stabilization System for Hinode (Solar-B) Solar Optical
    Telescope
Authors: Shimizu, T.; Nagata, S.; Tsuneta, S.; Tarbell, T.; Edwards,
   C.; Shine, R.; Hoffmann, C.; Thomas, E.; Sour, S.; Rehse, R.; Ito,
   O.; Kashiwagi, Y.; Tabata, M.; Kodeki, K.; Nagase, M.; Matsuzaki,
   K.; Kobayashi, K.; Ichimoto, K.; Suematsu, Y.
Bibcode: 2008SoPh..249..221S
Altcode:
  The Hinode Solar Optical Telescope (SOT) is the first space-borne
  visible-light telescope that enables us to observe magnetic-field
  dynamics in the solar lower atmosphere with 0.2 - 0.3 arcsec spatial
  resolution under extremely stable (seeing-free) conditions. To achieve
  precise measurements of the polarization with diffraction-limited
  images, stable pointing of the telescope (&lt;0.09 arcsec, 3σ) is
  required for solar images exposed on the focal plane CCD detectors. SOT
  has an image stabilization system that uses image displacements
  calculated from correlation tracking of solar granules to control
  a piezo-driven tip-tilt mirror. The system minimizes the motions
  of images for frequencies lower than 14 Hz while the satellite and
  telescope structural design damps microvibration in higher frequency
  ranges. It has been confirmed from the data taken on orbit that
  the remaining jitter is less than 0.03 arcsec (3σ) on the Sun. This
  excellent performance makes a major contribution to successful precise
  polarimetric measurements with 0.2 - 0.3 arcsec resolution.

Title: The Solar Optical Telescope for the Hinode Mission: An Overview
Authors: Tsuneta, S.; Ichimoto, K.; Katsukawa, Y.; Nagata, S.; Otsubo,
   M.; Shimizu, T.; Suematsu, Y.; Nakagiri, M.; Noguchi, M.; Tarbell,
   T.; Title, A.; Shine, R.; Rosenberg, W.; Hoffmann, C.; Jurcevich,
   B.; Kushner, G.; Levay, M.; Lites, B.; Elmore, D.; Matsushita, T.;
   Kawaguchi, N.; Saito, H.; Mikami, I.; Hill, L. D.; Owens, J. K.
Bibcode: 2008SoPh..249..167T
Altcode: 2008SoPh..tmp...74T; 2007arXiv0711.1715T
  The Solar Optical Telescope (SOT) aboard the Hinode satellite
  (formerly called Solar-B) consists of the Optical Telescope Assembly
  (OTA) and the Focal Plane Package (FPP). The OTA is a 50-cm
  diffraction-limited Gregorian telescope, and the FPP includes the
  narrowband filtergraph (NFI) and the broadband filtergraph (BFI), plus
  the Stokes Spectro-Polarimeter (SP). The SOT provides unprecedented
  high-resolution photometric and vector magnetic images of the
  photosphere and chromosphere with a very stable point spread function
  and is equipped with an image-stabilization system with performance
  better than 0.01 arcsec rms. Together with the other two instruments
  on Hinode (the X-Ray Telescope (XRT) and the EUV Imaging Spectrometer
  (EIS)), the SOT is poised to address many fundamental questions about
  solar magnetohydrodynamics. This paper provides an overview; the
  details of the instrument are presented in a series of companion papers.

Title: Frequent Occurrence of High-Speed Local Mass Downflows on
    the Solar Surface
Authors: Shimizu, T.; Lites, B. W.; Katsukawa, Y.; Ichimoto, K.;
   Suematsu, Y.; Tsuneta, S.; Nagata, S.; Kubo, M.; Shine, R. A.; Tarbell,
   T. D.
Bibcode: 2008ApJ...680.1467S
Altcode: 2008arXiv0804.1167S
  We report on new spectropolarimetric measurements with simultaneous
  filter imaging observation, revealing the frequent appearance of
  polarization signals indicating high-speed, probably supersonic,
  downflows that are associated with at least three different
  configurations of magnetic fields in the solar photosphere. The
  observations were carried out with the Solar Optical Telescope on
  board the Hinode satellite. High-speed downflows are excited when a
  moving magnetic feature is newly formed near the penumbral boundary of
  sunspots. Also, a new type of downflows is identified at the edge of
  sunspot umbra that lack accompanying penumbral structures. These may
  be triggered by the interaction of magnetic fields swept by convection
  with well-concentrated magnetic flux. Another class of high-speed
  downflows are observed in quiet Sun and sunspot moat regions. These are
  closely related to the formation of small concentrated magnetic flux
  patches. High-speed downflows of all types are transient time-dependent
  mass motions. These findings suggest that the excitation of supersonic
  mass flows are one of the key observational features of the dynamical
  evolution occurring in magnetic-field fine structures on the solar
  surface.

Title: Cooperative Observation of Ellerman Bombs between the Solar
    Optical Telescope aboard Hinode and Hida/Domeless Solar Telescope
Authors: Matsumoto, Takuma; Kitai, Reizaburo; Shibata, Kazunari;
   Nagata, Shin'ichi; Otsuji, Kenichi; Nakamura, Tahei; Watanabe, Hiroko;
   Tsuneta, Saku; Suematsu, Yoshinori; Ichimoto, Kiyoshi; Shimizu,
   Toshifumi; Katsukawa, Yukio; Tarbell, Theodore D.; Lites, Bruce W.;
   Shine, Richard A.; Title, Alan M.
Bibcode: 2008PASJ...60..577M
Altcode:
  High-resolution CaIIH broad-band filter images of NOAA10933 on 2007
  January 5 were obtained by the Solar Optical Telescope aboard the Hinode
  satellite. Many small-scale (∼1") bright points were observed outside
  the sunspot and inside the emerging flux region. We identified some of
  these bright points with Ellerman bombs (EBs) by using Hα images taken
  by the Domeless Solar Telescope at Hida observatory. The sub-arcsec
  structures of two EBs seen in CaIIH were studied in detail. Our
  observation showed the following two aspects: (1) The CaIIH bright
  points identified with EBs were associated with the bipolar magnetic
  field structures, as reported by previous studies. (2)The structure
  of the CaIIH bright points turned out to consist of the following two
  parts: a central elongated bright core (0.7" × 0.5") located along
  the magnetic neutral line and a diffuse halo (1.2"×1.8").

Title: The Solar Optical Telescope of Solar-B ( Hinode): The Optical
    Telescope Assembly
Authors: Suematsu, Y.; Tsuneta, S.; Ichimoto, K.; Shimizu, T.; Otsubo,
   M.; Katsukawa, Y.; Nakagiri, M.; Noguchi, M.; Tamura, T.; Kato, Y.;
   Hara, H.; Kubo, M.; Mikami, I.; Saito, H.; Matsushita, T.; Kawaguchi,
   N.; Nakaoji, T.; Nagae, K.; Shimada, S.; Takeyama, N.; Yamamuro, T.
Bibcode: 2008SoPh..249..197S
Altcode: 2008SoPh..tmp...26S
  The Solar Optical Telescope (SOT) aboard the Solar-B satellite (Hinode)
  is designed to perform high-precision photometric and polarimetric
  observations of the Sun in visible light spectra (388 - 668 nm)
  with a spatial resolution of 0.2 - 0.3 arcsec. The SOT consists of
  two optically separable components: the Optical Telescope Assembly
  (OTA), consisting of a 50-cm aperture Gregorian with a collimating lens
  unit and an active tip-tilt mirror, and an accompanying Focal Plane
  Package (FPP), housing two filtergraphs and a spectro-polarimeter. The
  optomechanical and optothermal performance of the OTA is crucial to
  attain unprecedented high-quality solar observations. We describe in
  detail the instrument design and expected stable diffraction-limited
  on-orbit performance of the OTA, the largest state-of-the-art solar
  telescope yet flown in space.

Title: Emergence of a helical flux rope and prominence formation
Authors: Okamoto, T. J.; Tsuneta, S.; Lites, B. W.; Kubo, M.; Yokoyama,
   T.; Berger, T. E.; Ichimoto, K.; Katsukawa, Y.; Nagata, S.; Shibata,
   K.; Shimizu, T.; Shine, R. A.; Suematsu, Y.; Tarbell, T. D.; Title,
   A. M.
Bibcode: 2008AGUSMSP43B..06O
Altcode:
  We report a discovery about emergence of a helical flux rope. The
  episode may be related to the formation and evolution of an active
  region prominence. Statistical studies by previous authors indicate that
  numerous prominences have the inverse-polarity configuration suggesting
  the helical magnetic configurations. There are two theoretical
  models about formation of such a coronal helical magnetic field in
  association with prominences: flux rope model and sheared-arcade
  model. We have so far no clear observational evidence to support
  either model. In order to find a clue about the formation of the
  prominence, we had continuous observations of NOAA AR 10953 with the
  SOT during 2007 April 28 to May 9. A prominence was located over the
  polarity inversion line in the south-east of the main sunspot. These
  observations provided us with a time series of vector magnetic fields
  on the photosphere under the prominence. We found four new features:
  (1) The abutting opposite-polarity regions on the two sides along
  the polarity inversion line first grew laterally in size and then
  narrowed. (2) These abutting regions contained vertically-weak,
  but horizontally-strong magnetic fields. (3) The orientations of
  the horizontal magnetic fields along the polarity inversion line on
  the photosphere gradually changed with time from a normal- polarity
  configuration to an inverse-polarity one. (4) The horizontal-magnetic
  field region was blueshifted. These indicate that helical flux rope
  emerges from below the photosphere into the corona along the polarity
  inversion line under the prominence. We suggest that this supply of a
  helical magnetic flux possibly into the corona is related to formation
  and maintenance of active-region prominences.

Title: Changes of Magnetic Structure in 3-D Associated with the X3.4
    Flare of 2006 December 13
Authors: Jing, J.; Wiegelmann, T.; Suematsu, Y.; Kubo, M.; Wang, H.
Bibcode: 2008AGUSMSP51C..02J
Altcode:
  Recent observations demonstrated that sunspot structure can change
  rapidly and irreversibly after flares. One of the most puzzling results
  is the increase in magnetic shear around flaring magnetic polarity
  inversion line after flares. However, all these observations were
  made at the photosphere level. We study the altitude variation of the
  non-potentiality of the magnetic fields associated with the 4B/X3.4
  flare of 2006 December 13. The vector magnetograms with unprecedented
  quality from Hinode before and after the flare are used as the boundary
  conditions to extrapolate the 3-dimensional non-linear force-free
  magnetic fields and the potential fields. The former are computed
  with the optimization algorithm and the latter with Green's function
  method. At the photosphere boundary, magnetic shear increases after the
  flare in a local area close to the flaring magnetic polarity inversion
  line. Two measures of the magnetic non-potentiality, the weighted mean
  shear θw and the total magnetic shear θwB, are calculated in this area
  at progressively higher altitude. By comparing their altitude variation
  profiles before and after the flare, we find that the non-potentiality
  of the local area increases after the flare below ~8 Mm and decreases
  from that height to ~70 Mm. Beyond 70 Mm, the magnetic fields approach
  potential for both times.

Title: Disintegration of Magnetic Flux in Decaying Sunspots as
    Observed with the Hinode/SOT
Authors: Kubo, M.; Lites, B. W.; Ichimoto, K.; Shimizu, T.; Suematsu,
   Y.; Katsukawa, Y.; Tarbell, T. D.; Shine, R. A.; Title, A. M.; Nagata,
   S.; Tsuneta, S.
Bibcode: 2008AGUSMSP31B..01K
Altcode:
  Continuous observations of sunspot penumbrae with the Solar Optical
  Telescope aboard Hinode clearly show that the outer boundary of the
  penumbra fluctuates around its averaged position. The penumbral outer
  boundary moves inward when granules appear in the outer penumbra. We
  discover that such granules appear one after another while moving
  magnetic features (MMFs) are separating from the penumbral "spines"
  (penumbral features having fields that are stronger and more vertical
  than their surroundings). These granules that appear in the outer
  penumbra often merge with bright features inside the penumbra that move
  with spines as they elongate toward the moat region. This suggests that
  convective motions around the penumbral outer boundary are related to
  disintegration of magnetic flux in the sunspot. We also find that dark
  penumbral filaments frequently elongate into the moat region in the
  vicinity of MMFs that detach from penumbral spines. Such elongating
  dark penumbral filaments correspond to nearly horizontal fields
  extending from the penumbra. Pairs of MMFs with positive and negative
  polarities are sometimes observed along the elongating dark penumbral
  filaments. This strongly supports the notion that such elongating dark
  penumbral filaments have magnetic fields with a "sea serpent"-like
  structure. Evershed flows, which are associated with the penumbral
  horizontal fields, may be related to detachment of the MMFs from the
  penumbral spines, as well as to the formation of the MMFs along the
  dark penumbral filaments that elongate into the moat region.

Title: Formation of Solar Magnetic Flux Tubes with Kilogauss Field
    Strength Induced by Convective Instability
Authors: Nagata, Shin'ichi; Tsuneta, Saku; Suematsu, Yoshinori;
   Ichimoto, Kiyoshi; Katsukawa, Yukio; Shimizu, Toshifumi; Yokoyama,
   Takaaki; Tarbell, Theodore D.; Lites, Bruce W.; Shine, Richard A.;
   Berger, Thomas E.; Title, Alan M.; Bellot Rubio, Luis R.; Orozco
   Suárez, David
Bibcode: 2008ApJ...677L.145N
Altcode:
  Convective instability has been a mechanism used to explain
  the formation of solar photospheric flux tubes with kG field
  strength. However, the turbulence of the Earth's atmosphere has
  prevented ground-based observers from examining the hypothesis
  with precise polarimetric measurement on the subarcsecond scale
  flux tubes. Here we discuss observational evidence of this scenario
  based on observations with the Solar Optical Telescope (SOT) aboard
  Hinode. The cooling of an equipartition field strength flux tube
  precedes a transient downflow reaching 6 km s<SUP>-1</SUP> and the
  intensification of the field strength to 2 kG. These observations
  agree very well with the theoretical predictions.

Title: Transient horizontal magnetic fields in solar plage regions
Authors: Ishikawa, R.; Tsuneta, S.; Ichimoto, K.; Isobe, H.; Katsukawa,
   Y.; Lites, B. W.; Nagata, S.; Shimizu, T.; Shine, R. A.; Suematsu,
   Y.; Tarbell, T. D.; Title, A. M.
Bibcode: 2008A&A...481L..25I
Altcode: 2008arXiv0802.1769I
  Aims:We report the discovery of isolated, small-scale emerging
  magnetic fields in a plage region with the Solar Optical Telescope
  aboard Hinode. <BR />Methods: Spectro-polarimetric observations were
  carried out with a cadence of 34 s for the plage region located near
  disc center. The vector magnetic fields are inferred by Milne-Eddington
  inversion. <BR />Results: The observations reveal widespread occurrence
  of transient, spatially isolated horizontal magnetic fields. The
  lateral extent of the horizontal magnetic fields is comparable to
  the size of photospheric granules. These horizontal magnetic fields
  seem to be tossed about by upflows and downflows of the granular
  convection. We also report an event that appears to be driven by the
  magnetic buoyancy instability. We refer to buoyancy-driven emergence
  as type 1 and convection-driven emergence as type 2. Although both
  events have magnetic field strengths of about 600 G, the filling
  factor of type 1 is a factor of two larger than that of type 2. <BR
  />Conclusions: Our finding suggests that the granular convection in
  the plage regions is characterized by a high rate of occurrence of
  granular-sized transient horizontal fields.

Title: Net circular polarization of sunspots in high spatial
    resolution
Authors: Ichimoto, K.; Tsuneta, S.; Suematsu, Y.; Katsukawa, Y.;
   Shimizu, T.; Lites, B. W.; Kubo, M.; Tarbell, T. D.; Shine, R. A.;
   Title, A. M.; Nagata, S.
Bibcode: 2008A&A...481L...9I
Altcode:
  Context: Net circular polarization (NCP) of spectral lines in
  sunspots has been most successfully explained by the presense of
  discontinuities in the magnetic field inclination and flow velocity
  along the line-of-sight in the geometry of the embedded flux tube model
  of penumbrae (Δγ-effect). <BR />Aims: The fine scale structure of
  NCP in a sunspot is examined with special attention paid to spatial
  relations of the Evershed flow to confirm the validity of the present
  interpretation of the NCP of sunspots. <BR />Methods: High resolution
  spectro-polarimetric data of a positive-polarity sunspot obtained
  by the Solar Optical Telescope aboard Hinode are analysed. <BR
  />Results: A positive NCP is associated with the Evershed flow
  channels in both limb-side and disk center-side penumbrae and with
  upflows in the penumbra at disk center. The negative NCP in the disk
  center-side penumbra is generated in inter-Evershed flow channels. <BR
  />Conclusions: The first result is apparently inconsistent with the
  current explanation of NCP with the Δγ-effect but rather suggests a
  positive correlation between the magnetic field strength and the flow
  velocity as the cause of the NCP. The second result serves as strong
  evidence for the presence of gas flows in inter-Evershed flow channels.

Title: Changes of Magnetic Structure in Three Dimensions Associated
    with the X3.4 Flare of 2006 December 13
Authors: Jing, Ju; Wiegelmann, Thomas; Suematsu, Yoshinori; Kubo,
   Masahito; Wang, Haimin
Bibcode: 2008ApJ...676L..81J
Altcode:
  Recent observations demonstrated that sunspot structure can change
  rapidly and irreversibly after flares. One of the most puzzling results
  is the increase in magnetic shear around the flaring magnetic polarity
  inversion line after flares. However, all these observations were
  made at the photosphere level. In this Letter, we study the altitude
  variation of the nonpotentiality of the magnetic fields associated
  with the 4B/X3.4 flare of 2006 December 13. The vector magnetograms
  with unprecedented quality from Hinode before and after the flare are
  used as the boundary conditions to extrapolate the three-dimensional
  nonlinear force-free magnetic fields and the potential fields. The
  former are computed with the optimization algorithm and the latter with
  the Green's function method. At the photosphere boundary, magnetic shear
  increases after the flare in a local area close to the flaring magnetic
  polarity inversion line. Two measures of the magnetic nonpotentiality,
  the weighted mean shear θ<SUB>w</SUB> and the total magnetic shear
  θ<SUB>w</SUB>B, are calculated in this area at progressively higher
  altitude. By comparing their altitude variation profiles before and
  after the flare, we find that the nonpotentiality of the local area
  increases after the flare below ~8 Mm and decreases from that height
  to ~70 Mm. Beyond 70 Mm, the magnetic fields approach potential for
  both times.

Title: Hinode SOT Observations of Solar Quiescent Prominence Dynamics
Authors: Berger, Thomas E.; Shine, Richard A.; Slater, Gregory L.;
   Tarbell, Theodore D.; Title, Alan M.; Okamoto, Takenori J.; Ichimoto,
   Kiyoshi; Katsukawa, Yukio; Suematsu, Yoshinori; Tsuneta, Saku; Lites,
   Bruce W.; Shimizu, Toshifumi
Bibcode: 2008ApJ...676L..89B
Altcode:
  We report findings from multihour 0.2'' resolution movies of
  solar quiescent prominences (QPs) observed with the Solar Optical
  Telescope (SOT) on the Hinode satellite. The observations verify
  previous findings of filamentary downflows and vortices in QPs. SOT
  observations also verify large-scale transverse oscillations in QPs,
  with periods of 20-40 minutes and amplitudes of 2-5 Mm. The upward
  propagation speed of several waves is found to be ~10 km s<SUP>-1</SUP>,
  comparable to the sound speed of a 10,000 K plasma, implying that
  the waves are magnetoacoustic in origin. Most significantly, Hinode
  SOT observations reveal that dark, episodic upflows are common in
  QPs. The upflows are 170-700 km in width, exhibit turbulent flow,
  and rise with approximately constant speeds of ~20 km s<SUP>-1</SUP>
  from the base of the prominence to heights of ~10-20 Mm. The upflows
  are visible in both the Ca II H-line and Hα bandpasses of SOT. The new
  flows are seen in about half of the QPs observed by SOT to date. The
  dark upflows resemble buoyant starting plumes in both their velocity
  profile and flow structure. We discuss thermal and magnetic mechanisms
  as possible causes of the plumes.

Title: Emergence of a Helical Flux Rope under an Active Region
    Prominence
Authors: Okamoto, Takenori J.; Tsuneta, Saku; Lites, Bruce W.; Kubo,
   Masahito; Yokoyama, Takaaki; Berger, Thomas E.; Ichimoto, Kiyoshi;
   Katsukawa, Yukio; Nagata, Shin'ichi; Shibata, Kazunari; Shimizu,
   Toshifumi; Shine, Richard A.; Suematsu, Yoshinori; Tarbell, Theodore
   D.; Title, Alan M.
Bibcode: 2008ApJ...673L.215O
Altcode: 2008arXiv0801.1956O
  Continuous observations were obtained of NOAA AR 10953 with the Solar
  Optical Telescope (SOT) on board the Hinode satellite from 2007 April
  28 to May 9. A prominence was located over the polarity inversion
  line (PIL) to the southeast of the main sunspot. These observations
  provided us with a time series of vector magnetic fields on the
  photosphere under the prominence. We found four features: (1) The
  abutting opposite-polarity regions on the two sides along the PIL first
  grew laterally in size and then narrowed. (2) These abutting regions
  contained vertically weak but horizontally strong magnetic fields. (3)
  The orientations of the horizontal magnetic fields along the PIL on
  the photosphere gradually changed with time from a normal-polarity
  configuration to an inverse-polarity one. (4) The horizontal magnetic
  field region was blueshifted. These indicate that helical flux rope
  was emerging from below the photosphere into the corona along the PIL
  under the preexisting prominence. We suggest that this supply of a
  helical magnetic flux to the corona is associated with evolution and
  maintenance of active region prominences.

Title: The Horizontal Magnetic Flux of the Quiet-Sun Internetwork
    as Observed with the Hinode Spectro-Polarimeter
Authors: Lites, B. W.; Kubo, M.; Socas-Navarro, H.; Berger, T.; Frank,
   Z.; Shine, R.; Tarbell, T.; Title, A.; Ichimoto, K.; Katsukawa, Y.;
   Tsuneta, S.; Suematsu, Y.; Shimizu, T.; Nagata, S.
Bibcode: 2008ApJ...672.1237L
Altcode:
  Observations of very quiet Sun using the Solar Optical
  Telescope/Spectro-Polarimeter (SOT/SP) aboard the Hinode spacecraft
  reveal that the quiet internetwork regions are pervaded by horizontal
  magnetic flux. The spatial average horizontal apparent flux density
  derived from wavelength-integrated measures of Zeeman-induced linear
  polarization is B<SUP>T</SUP><SUB>app</SUB> = 55 Mx cm <SUP>-2</SUP>, as
  compared to the corresponding average vertical apparent flux density of
  | B<SUP>L</SUP><SUB>app</SUB>| = 11 Mx cm <SUP>-2</SUP>. Distributions
  of apparent flux density are presented. Magnetic fields are organized on
  mesogranular scales, with both horizontal and vertical fields showing
  "voids" of reduced flux density of a few granules spatial extent. The
  vertical fields are concentrated in the intergranular lanes, whereas the
  stronger horizontal fields are somewhat separated spatially from the
  vertical fields and occur most commonly at the edges of the bright
  granules. High-S/N observations from disk center to the limb help
  to constrain possible causes of the apparent imbalance between |
  B<SUP>L</SUP><SUB>app</SUB>| and B<SUP>T</SUP><SUB>app</SUB>, with
  unresolved structures of linear dimension on the surface smaller by at
  least a factor of 2 relative to the SOT/SP angular resolution being one
  likely cause of this discrepancy. Other scenarios for explaining this
  imbalance are discussed. The horizontal fields are likely the source of
  the "seething" fields of the quiet Sun discovered by Harvey et al. The
  horizontal fields may also contribute to the "hidden" turbulent flux
  suggested by studies involving Hanle effect depolarization of scattered
  radiation.

Title: Hinode Observations of Flux Emergence in Quiet and Active
    Regions
Authors: Lites, B. W.; Centeno, R.; Kubo, M.; Socas-Navarro, H. Berger,
   T.; Frank, Z.; Shine, R.; Tarbell, T.; Title, A.; Ichimoto, K.;
   Katsukawa, Y.; Tsuneta, S.; Suematsu, Y.; Shimizu, T.; Nagata, S.
Bibcode: 2008ASPC..383...71L
Altcode:
  We review briefly the observational understanding of emergence of
  flux in both the quiet Sun and active regions in the light of first
  results from the joint Japan/US/UK Hinode mission. That spacecraft
  is now providing us with our first continuous, high resolution
  measurements of the photospheric vector magnetic field, along with
  high resolution observations of the thermal and dynamic properties
  of the chromosphere and corona. This review is intended to present a
  few very early results and to highlight the potential for discovery
  offered by this extraordinary new mission. The discovery of ubiquitous
  horizontal magnetic flux in the quiet internetwork regions is presented.

Title: Mangetic field properties at the footpoints of solar
    microflares (active-region transient brightenings)
Authors: Shimizu, T.; Kano, R.; Katsukawa, Y.; Kubo, M.; Deluca, E.;
   Ichimoto, K.; Lites, B.; Nagata, S.; Sakao, T.; Shine, R.; Suematsu,
   Y.; Tarbell, T.; Title, A.; Tsuneta, S.
Bibcode: 2007AGUFMSH52C..06S
Altcode:
  Solar active regions produce numerous numbers of small-scale explosive
  energy releases, i.e., microflares, which are captured by imaging
  observations in soft X-rays as transient brightenings of small-scale
  coronal loops. Thanks to advanced performance of X-Ray Telescope (XRT)
  onboard the Hinode satellite, we can investigate finer structure
  of the brightening X-ray sources in more details than we did with
  Yohkoh data. One of important questions on microflares is what causes
  microflares. The simultaneous visible-light observations by the Solar
  Optical Telescope (SOT) allow us to explore magnetic activities
  and magnetic field configuration at the photospheric footpoints
  of brightening loops, giving key observations to investigate the
  question. For our investigations of corona-photosphere magnetic
  coupling, we have established co-alignment between SOT and XRT
  with accuracy better than 1 arcsec (Shimizu et al. 2007, PASJ in
  press). It turns out that Ca II H observations are very useful
  to identify the exact positions of footpoints of X-ray transient
  brightening loops. Small "Kernels" are sometimes observed in Ca II H
  and they may be signature of highly accelerated non-thermal particles
  impinging on chromosphere. As already shown in Shimizu et al.(2002),
  frequent transient brightenings are observed at the locations where
  emerging activities are on going. However, another type of brightening
  triggering mechanism should exist to explain some observed multiple-loop
  brightenings. In the multiple-loop brightenings, multiple loops are
  magnetically in parallel with each other and no apparent magnetic
  activities, such as emerging and canceling, are observed at and near
  the footpoints. This paper will present SOT observations of some
  microflares observed with XRT.

Title: Small-Scale Jetlike Features in Penumbral Chromospheres
Authors: Katsukawa, Y.; Berger, T. E.; Ichimoto, K.; Lites, B. W.;
   Nagata, S.; Shimizu, T.; Shine, R. A.; Suematsu, Y.; Tarbell, T. D.;
   Title, A. M.; Tsuneta, S.
Bibcode: 2007Sci...318.1594K
Altcode:
  We observed fine-scale jetlike features, referred to as penumbral
  microjets, in chromospheres of sunspot penumbrae. The microjets
  were identified in image sequences of a sunspot taken through a Ca II
  H-line filter on the Solar Optical Telescope on board the Japanese solar
  physics satellite Hinode. The microjets’ small width of 400 kilometers
  and short duration of less than 1 minute make them difficult to identify
  in existing observations. The microjets are possibly caused by magnetic
  reconnection in the complex magnetic configuration in penumbrae and
  have the potential to heat the corona above a sunspot.

Title: Chromospheric Alfvénic Waves Strong Enough to Power the
    Solar Wind
Authors: De Pontieu, B.; McIntosh, S. W.; Carlsson, M.; Hansteen,
   V. H.; Tarbell, T. D.; Schrijver, C. J.; Title, A. M.; Shine, R. A.;
   Tsuneta, S.; Katsukawa, Y.; Ichimoto, K.; Suematsu, Y.; Shimizu, T.;
   Nagata, S.
Bibcode: 2007Sci...318.1574D
Altcode:
  Alfvén waves have been invoked as a possible mechanism for the heating
  of the Sun's outer atmosphere, or corona, to millions of degrees and
  for the acceleration of the solar wind to hundreds of kilometers per
  second. However, Alfvén waves of sufficient strength have not been
  unambiguously observed in the solar atmosphere. We used images of
  high temporal and spatial resolution obtained with the Solar Optical
  Telescope onboard the Japanese Hinode satellite to reveal that the
  chromosphere, the region sandwiched between the solar surface and
  the corona, is permeated by Alfvén waves with strong amplitudes on
  the order of 10 to 25 kilometers per second and periods of 100 to
  500 seconds. Estimates of the energy flux carried by these waves and
  comparisons with advanced radiative magnetohydrodynamic simulations
  indicate that such Alfvén waves are energetic enough to accelerate
  the solar wind and possibly to heat the quiet corona.

Title: Chromospheric Anemone Jets as Evidence of Ubiquitous
    Reconnection
Authors: Shibata, Kazunari; Nakamura, Tahei; Matsumoto, Takuma; Otsuji,
   Kenichi; Okamoto, Takenori J.; Nishizuka, Naoto; Kawate, Tomoko;
   Watanabe, Hiroko; Nagata, Shin'ichi; UeNo, Satoru; Kitai, Reizaburo;
   Nozawa, Satoshi; Tsuneta, Saku; Suematsu, Yoshinori; Ichimoto, Kiyoshi;
   Shimizu, Toshifumi; Katsukawa, Yukio; Tarbell, Theodore D.; Berger,
   Thomas E.; Lites, Bruce W.; Shine, Richard A.; Title, Alan M.
Bibcode: 2007Sci...318.1591S
Altcode: 2008arXiv0810.3974S
  The heating of the solar chromosphere and corona is a long-standing
  puzzle in solar physics. Hinode observations show the ubiquitous
  presence of chromospheric anemone jets outside sunspots in active
  regions. They are typically 3 to 7 arc seconds = 2000 to 5000 kilometers
  long and 0.2 to 0.4 arc second = 150 to 300 kilometers wide, and their
  velocity is 10 to 20 kilometers per second. These small jets have an
  inverted Y-shape, similar to the shape of x-ray anemone jets in the
  corona. These features imply that magnetic reconnection similar to that
  in the corona is occurring at a much smaller spatial scale throughout
  the chromosphere and suggest that the heating of the solar chromosphere
  and corona may be related to small-scale ubiquitous reconnection.

Title: Twisting Motions of Sunspot Penumbral Filaments
Authors: Ichimoto, K.; Suematsu, Y.; Tsuneta, S.; Katsukawa, Y.;
   Shimizu, T.; Shine, R. A.; Tarbell, T. D.; Title, A. M.; Lites, B. W.;
   Kubo, M.; Nagata, S.
Bibcode: 2007Sci...318.1597I
Altcode:
  The penumbra of a sunspot is composed of numerous thin, radially
  extended, bright and dark filaments carrying outward gas flows
  (the Evershed flow). Using high-resolution images obtained by the
  Solar Optical Telescope aboard the solar physics satellite Hinode, we
  discovered a number of penumbral bright filaments revealing twisting
  motions about their axes. These twisting motions are observed only
  in penumbrae located in the direction perpendicular to the symmetry
  line connecting the sunspot center and the solar disk center, and
  the direction of the twist (that is, lateral motions of intensity
  fluctuation across filaments) is always from limb side to disk-center
  side. Thus, the twisting feature is not an actual twist or turn of
  filaments but a manifestation of dynamics of penumbral filaments with
  three-dimensional radiative transfer effects.

Title: Hinode SOT observations of plume upflows and cascading
    downflows in quiescent solar prominences
Authors: Berger, T.; Shine, R.; Slater, G.; Tarbell, T.; Title, A.;
   Lites, B.; Tsuneta, S.; Okamoto, T. J.; Ichimoto, K.; Katsukawa, Y.;
   Sekii, T.; Suematsu, Y.; Shimizu, T.
Bibcode: 2007AGUFMSH53A1065B
Altcode:
  We present several Hinode SOT filtergram movies of quiescent solar
  prominences that show newly discovered "plume-like" upflows and
  cascading "waterfall-like" downflows that persist for the entire
  multi-hour duration of the observations. The flow speeds are on the
  order of 10 km/sec with typical widths of 400-700 km. Preliminary
  calculations show that if the upflows are buoyancy driven, the
  associated thermal perturbation is on the order of 10,000 K, sufficient
  to explain the dark appearance of the upflows in the interference
  filter passbands. In addition we observe rotational vortices and
  body oscillations within the prominences. These new observations
  challenge current magnetostatic models of solar prominences by showing
  that prominence plasmas are in constant motion, often in directions
  perpendicular to the magnetic field lines proposed by the models. TRACE,
  Hinode/EIS, and Hinode/XRT observations are used to investigate the
  differential topology of the flows across temperature regimes.

Title: Coronal Transverse Magnetohydrodynamic Waves in a Solar
    Prominence
Authors: Okamoto, T. J.; Tsuneta, S.; Berger, T. E.; Ichimoto, K.;
   Katsukawa, Y.; Lites, B. W.; Nagata, S.; Shibata, K.; Shimizu, T.;
   Shine, R. A.; Suematsu, Y.; Tarbell, T. D.; Title, A. M.
Bibcode: 2007Sci...318.1577O
Altcode: 2008arXiv0801.1958O
  Solar prominences are cool 10<SUP>4</SUP> kelvin plasma clouds
  supported in the surrounding 10<SUP>6</SUP> kelvin coronal plasma by
  as-yet-undetermined mechanisms. Observations from Hinode show fine-scale
  threadlike structures oscillating in the plane of the sky with periods
  of several minutes. We suggest that these represent Alfvén waves
  propagating on coronal magnetic field lines and that these may play
  a role in heating the corona.

Title: Quiet-Sun Internetwork Magnetic Fields from the Inversion of
    Hinode Measurements
Authors: Orozco Suárez, D.; Bellot Rubio, L. R.; del Toro Iniesta,
   J. C.; Tsuneta, S.; Lites, B. W.; Ichimoto, K.; Katsukawa, Y.; Nagata,
   S.; Shimizu, T.; Shine, R. A.; Suematsu, Y.; Tarbell, T. D.; Title,
   A. M.
Bibcode: 2007ApJ...670L..61O
Altcode: 2007arXiv0710.1405O
  We analyze Fe I 630 nm observations of the quiet Sun at disk center
  taken with the spectropolarimeter of the Solar Optical Telescope aboard
  the Hinode satellite. A significant fraction of the scanned area,
  including granules, turns out to be covered by magnetic fields. We
  derive field strength and inclination probability density functions from
  a Milne-Eddington inversion of the observed Stokes profiles. They show
  that the internetwork consists of very inclined, hG fields. As expected,
  network areas exhibit a predominance of kG field concentrations. The
  high spatial resolution of Hinode's spectropolarimetric measurements
  brings to an agreement the results obtained from the analysis of
  visible and near-infrared lines.

Title: Center-to-Limb Variation of Stokes V Asymmetries in Solar
    Pores Observed with the Hinode Spectro-Polarimeter
Authors: Morinaga, Shuji; Nagata, Shin'ichi; Ichimoto, Kiyoshi;
   Suematsu, Yoshinori; Tsuneta, Saku; Katsukawa, Yukio; Shimizu,
   Toshifumi; Shine, Richard A.; Tarbell, Theodore D.; Title, Alan M.;
   Lites, Bruce; Kubo, Masahito; Sakurai, Takashi
Bibcode: 2007PASJ...59S.613M
Altcode:
  Here we present spectro-polarimetric measurements of several pores
  and the surrounding regions taken with the Solar Optical Telescope
  aboard Hinode at various viewing angles. We analyzed the Stokes V
  area asymmetry, and confirmed that it is depressed at the center of
  the pores, while it shows large positive values (a blue lobe larger
  than a red lobe) in the surrounding area; this is consistent with a
  previous report. In addition to this ring of positive asymmetry, we
  found regions of alternating positive and negative area asymmetries
  when weak V regions were observed near the solar limb. The positive
  asymmetry occurs on the disk-center side and the negative asymmetry
  on the limb side of the magnetic concentrations. These center-to-limb
  variations of the Stokes V area asymmetry can be interpreted as being
  a systematic inflow of plasma into the magnetic concentrations from
  their surroundings.

Title: Initial Results on Line-of-Sight Field Calibrations of SP/NFI
    Data Taken by SOT/Hinode
Authors: Chae, Jongchul; Moon, Yong-Jae; Park, Young-Deuk; Ichimoto,
   Kiyoshi; Sakurai, Takashi; Suematsu, Yoshinori; Tsuneta, Saku;
   Katsukawa, Yukio; Shimizu, Toshifumi; Shine, Richard A.; Tarbell,
   Theodore D.; Title, Alan M.; Lites, Bruce; Kubo, Masahito; Nagata,
   Shin'ichi; Yokoyama, Takaaki
Bibcode: 2007PASJ...59S.619C
Altcode:
  We present initial results on the line-of-sight field calibration
  of the two kinds of Stokes I and V data taken by the Solar Optical
  Telescope on the satellite Hinode: spectral profiles of Stokes I and V
  parameters recorded on the Spectro-polarimeter (SP), and monochromatic
  images of the same parameters recorded on the Narrow-band Filter Imager
  (NFI). By applying the center-of-gravity method to the SP data of
  AR10930 taken on 2006 December 11, we determined the line-of-sight field
  at every location in the active region. As a result, we found that the
  line-of-sight field strength ranges up to 2kG in plages, even without
  taking into account the filling factor, and up to 3.5kG or higher values
  inside the umbra of the major sunspot. We calibrated the NFI data in
  reference to the field determined from the SP data. In regions outside
  the sunspots and the penumbral regions, we adopted a linear relation,
  B<SUB>||</SUB> = βV / I, between the circular polarization, V / I,
  and the line-of-sight field strength, B<SUB>||</SUB>, and obtained β =
  23.5kG in regions outside the sunspots, and β = 12.0kG in penumbral
  regions. In umbral regions of sunspots, a first-order polynomial was
  adopted to model the reversal of the polarization signal over the
  field strength.

Title: Response of the Solar Atmosphere to Magnetic Flux Emergence
    from Hinode Observations
Authors: Li, Hui; Sakurai, Takashi; Ichimito, Kiyoshi; Suematsu,
   Yoshinori; Tsuneta, Saku; Katsukawa, Yukio; Shimizu, Toshifumi; Shine,
   Richard A.; Tarbell, Theodore D.; Title, Alan M.; Lites, Bruce; Kubo,
   Masahito; Nagata, Shin'ichi; Kotoku, Jun; Shibasaki, Kiyoto; Saar,
   Steven H.; Bobra, Monica
Bibcode: 2007PASJ...59S.643L
Altcode:
  No abstract at ADS

Title: Initial Helioseismic Observations by Hinode/SOT
Authors: Sekii, Takashi; Kosovichev, Alexander G.; Zhao, Junwei;
   Tsuneta, Saku; Shibahashi, Hiromoto; Berger, Thomas E.; Ichimoto,
   Kiyoshi; Katsukawa, Yukio; Lites, Bruce; Nagata, Shin'ichi; Shimizu,
   Toshifumi; Shine, Richard A.; Suematsu, Yoshinori; Tarbell, Theodore
   D.; Title, Alan M.
Bibcode: 2007PASJ...59S.637S
Altcode: 2007arXiv0709.1806S
  Results from initial helioseismic observations by the Solar Optical
  Telescope on-board Hinode are reported. It has been demonstrated
  that intensity oscillation data from the Broadband Filter Imager
  can be used for various helioseismic analyses. The k - ω power
  spectra, as well as the corresponding time-distance cross-correlation
  function, which promise high-resolution time-distance analysis below
  the 6-Mm travelling distance, were obtained for G-band and CaII-H
  data. Subsurface supergranular patterns were observed from our first
  time-distance analysis. The results show that the solar oscillation
  spectrum is extended to much higher frequencies and wavenumbers, and
  the time-distance diagram is extended to much shorter travel distances
  and times than were observed before, thus revealing great potential
  for high-resolution helioseismic observations from Hinode.

Title: Hinode Observations of Horizontal Quiet Sun Magnetic Flux
    and the ``Hidden Turbulent Magnetic Flux''
Authors: Lites, Bruce; Socas-Navarro, Hector; Kubo, Masahito; Berger,
   Thomas; Frank, Zoe; Shine, Richard A.; Tarbell, Theodore D.; Title,
   Alan M.; Ichimoto, Kiyoshi; Katsukawa, Yukio; Tsuneta, Saku; Suematsu,
   Yoshinori; Shimizu, Toshifumi
Bibcode: 2007PASJ...59S.571L
Altcode:
  We present observations of magnetic fields of the very quiet Sun
  near disk center using the Spectro-Polarimeter of the Solar Optical
  Telescope aboard the Hinode satellite. These observations reveal for
  the first time the ubiquitous presence of horizontal magnetic fields in
  the internetwork regions. The horizontal fields are spatially distinct
  from the vertical fields, demonstrating that they are not arising mainly
  from buffeting of vertical flux tubes by the granular convection. The
  horizontal component has an average ``apparent flux density'' of
  55Mxcm<SUP>-2</SUP> (assuming the horizontal field structures are
  spatially resolved), in contrast to the average apparent vertical flux
  density of 11Mxcm<SUP>-2</SUP>. The vertical fields reside mainly in
  the intergranular lanes, whereas the horizontal fields occur mainly
  over the bright granules, with a preference to be near the outside
  edge of the bright granules. The large apparent imbalance of vertical
  and horizontal flux densities is discussed, and several scenarios are
  presented to explain this imbalance.

Title: Strategy for the Inversion of Hinode Spectropolarimetric
    Measurements in the Quiet Sun
Authors: Orozco Suárez, David; Bellot Rubio, Luis R.; Del Toro
   Iniesta, Jose Carlos; Tsuneta, Saku; Lites, Bruce; Ichimoto, Kiyoshi;
   Katsukawa, Yukio; Nagata, Shin'ichi; Shimizu, Toshifumi; Shine,
   Richard A.; Suematsu, Yoshinori; Tarbell, Theodore D.; Title, Alan M.
Bibcode: 2007PASJ...59S.837O
Altcode: 2007arXiv0709.2033O
  In this paper we propose an inversion strategy for the analysis of
  spectropolarimetric measurements taken by Hinode in the quiet Sun. The
  Spectro-Polarimeter of the Solar Optical Telescope aboard Hinode records
  the Stokes spectra of the FeI line pair at 630.2nm with unprecendented
  angular resolution, high spectral resolution, and high sensitivity. We
  discuss the need to consider a local stray-light contamination to
  account for the effects of telescope diffraction. The strategy is
  applied to observations of a wide quiet Sun area at disk center. Using
  these data we examine the influence of noise and initial guess models
  in the inversion results. Our analysis yields the distributions of
  magnetic field strengths and stray-light factors. They show that quiet
  Sun internetwork regions consist mainly of hG fields with stray-light
  contamination of about 0.8.

Title: Hinode Observations of a Vector Magnetic Field Change
    Associated with a Flare on 2006 December 13
Authors: Kubo, Masahito; Yokoyama, Takaaki; Katsukawa, Yukio; Lites,
   Bruce; Tsuneta, Saku; Suematsu, Yoshinori; Ichimoto, Kiyoshi; Shimizu,
   Toshifumi; Nagata, Shin'ichi; Tarbell, Theodore D.; Shine, Richard A.;
   Title, Alan M.; Elmore David
Bibcode: 2007PASJ...59S.779K
Altcode: 2007arXiv0709.2397K
  Continuous observations of the flare productive active region 10930
  were successfully carried out with the Solar Optical Telescope aboard
  the Hinode spacecraft during 2006 December 6 to 19. We focused on the
  evolution of photospheric magnetic fields in this active region, and the
  magnetic field properties at the site of the X3.4 class flare, using
  a time series of vector field maps with high spatial resolution. The
  X3.4 class flare occurred on 2006 December 13 at the apparent
  collision site between the large, opposite polarity umbrae. Elongated
  magnetic structures with alternatingly positive and negative polarities
  resulting from flux emergence appeared one day before the flare in the
  collision site penumbra. Subsequently, the polarity inversion line
  at the collision site became very complicated. The number of bright
  loops in CaII H increased during the formation of these elongated
  magnetic structures. Flare ribbons and bright loops evolved along
  the polarity inversion line and one footpoint of the bright loop was
  located in a region having a large departure of the field azimuth angle
  with respect to its surroundings. SOT observations with high spatial
  resolution and high polarization precision revealed temporal change in
  the fine structure of magnetic fields at the flare site: some parts of
  the complicated polarity inversion line then disappeared, and in those
  regions the azimuth angle of the photospheric magnetic field changed by
  about 90°, becoming more spatially uniform within the collision site.

Title: The Analysis of Penumbral Fine Structure Using an Advanced
    Inversion Technique
Authors: Jurcák, Jan; Bellot Rubio, Luis; Ichimoto, Kiyoshi;
   Katsukawa, Yukio; Lites, Bruce; Nagata, Shin'ichi; Shimizu, Toshifumi;
   Suematsu, Yoshinori; Tarbell, Theodore D.; Title, Alan M.; Tsuneta,
   Saku
Bibcode: 2007PASJ...59S.601J
Altcode: 2007arXiv0707.1560J
  We present a method to study the penumbral fine structure using data
  obtained by the spectropolarimeter on board Hinode. For the first
  time, the penumbral filaments can be considered as being resolved in
  spectropolarimetric measurements. This enables us to use inversion
  codes with only one-component model atmospheres, and thus to assign
  the obtained stratifications of the plasma parameters directly to the
  penumbral fine structure. This approach was applied to the limb-side
  part of the penumbra in the active region NOAA10923. Preliminary results
  show a clear dependence of the plasma parameters on the continuum
  intensity in the inner penumbra, i.e., a weaker and horizontal magnetic
  field along with an increased line-of-sight velocity are found in the
  low layers of the bright filaments. The results in the mid penumbra
  are ambiguous, and future analyses are necessary to unveil the magnetic
  field structure and other plasma parameters there.

Title: Fine-Scale Structures of the Evershed Effect Observed by the
    Solar Optical Telescope aboard Hinode
Authors: Ichimoto, Kiyoshi; Shine, Richard A.; Lites, Bruce; Kubo,
   Masahito; Shimizu, Toshifumi; Suematsu, Yoshinori; Tsuneta, Saku;
   Katsukawa, Yukio; Tarbell, Theodore D.; Title, Alan M.; Nagata,
   Shin'ichi; Yokoyama, Takaaki; Shimojo, Masumi
Bibcode: 2007PASJ...59S.593I
Altcode:
  The small-scale structure of the Evershed effect is being studied
  using data obtained by the Spectropolarimeter and the Broadband Filter
  Imager of the Solar Optical Telescope aboard Hinode. We find that the
  Evershed flow starts at the leading edge of inwardly migrating bright
  penumbral grains, and turns to nearly a horizontal flow preferentially
  in the dark lanes of the penumbra. A number of small elongated regions
  that have an upward motion of ∼ 1kms<SUP>-1</SUP> are found in the
  deep photosphere distributed over the penumbra. They are cospatial
  with bright grains and have relatively horizontal magnetic fields. A
  number of patches having a strong downward motion associated with the
  opposite magnetic polarity from the sunspot are also found in the mid
  and outer penumbra. They could be identified as foot points of the
  Evershed flow channels, though the identification of individual pairs
  is not straightforward. Our results provide strong support for some
  recent findings from ground-based high-resolution observations, and
  are in general agreement with the well-known picture of the uncombed
  structure of the penumbra, in which the penumbrae consist of rising
  flux tubes carrying nearly horizontal Evershed flows embedded in more
  vertical background magnetic fields.

Title: Flare Ribbons Observed with G-band and FeI 6302Å, Filters
    of the Solar Optical Telescope on Board Hinode
Authors: Isobe, Hiroaki; Kubo, Masahito; Minoshima, Takashi; Ichimoto,
   Kiyoshi; Katsukawa, Yukio; Tarbell, Theodore D.; Tsuneta, Saku; Berger,
   Thomas E.; Lites, Bruce; Nagata, Shin'ichi; Shimizu, Toshifumi; Shine,
   Richard A.; Suematsu, Yoshinori; Title, Alan M.
Bibcode: 2007PASJ...59S.807I
Altcode: 2007arXiv0711.3946I
  The Solar Optical Telescope (SOT) on board the Hinode satellite observed
  an X3.4 class flare on 2006 December 13. A typical two-ribbon structure
  was observed, not only in the chromospheric CaII H line, but also in
  the G-band and FeI 6302Å line. The high-resolution, seeing-free images
  achieved by SOT revealed, for the first time, sub-arcsec fine structures
  of the ``white light'' flare. The G-band flare ribbons on sunspot
  umbrae showed a sharp leading edge, followed by a diffuse inside,
  as well as a previously known core-halo structure. The underlying
  structures, such as umbral dots, penumbral filaments, and granules,
  were visible in the flare ribbons. Assuming that the sharp leading
  edge was directly heated by a particle beam and the diffuse parts were
  heated by radiative back-warming, we estimated the depth of the diffuse
  flare emission using an intensity profile of the flare ribbon. We found
  that the depth of the diffuse emission was about 100km or less from
  the height of the source of radiative back-warming. The flare ribbons
  were also visible in the Stokes-V images of FeI 6302Å, as a transient
  polarity reversal. This is probably related to a ``magnetic transient''
  reported in the literature. The intensity increase in Stokes-I images
  indicates that the FeI 6302Å line was significantly deformed by the
  flare, which may cause such a magnetic transient.

Title: Small-Scale Magnetic-Flux Emergence Observed with Hinode
    Solar Optical Telescope
Authors: Otsuji, Kenichi; Shibata, Kazunari; Kitai, Reizaburo; Ueno,
   Satoru; Nagata, Shin'ichi; Matsumoto, Takuma; Nakamura, Tahei;
   Watanabe, Hiroko; Tsuneta, Saku; Suematsu, Yoshinori; Ichimoto,
   Kiyoshi; Shimizu, Toshifumi; Katsukawa, Yukio; Tarbell, Theodore D.;
   Lites, Bruce; Shine, Richard A.; Title Alan M.
Bibcode: 2007PASJ...59S.649O
Altcode: 2007arXiv0709.3207O
  We observed small-scale magnetic-flux emergence in a sunspot moat region
  by the Solar Optical Telescope (SOT) aboard the Hinode satellite. We
  analyzed filtergram images observed at wavelengths of Fe 6302Å, G band,
  and CaII H. In Stokes I images of Fe 6302Å, emerging magnetic flux was
  recognized as dark lanes. In the G band, they showed to be their shapes
  almost the same as in Stokes I images. These magnetic fluxes appeared
  as dark filaments in CaII H images. Stokes V images of Fe 6302Å showed
  pairs of opposite polarities at footpoints of each filament. These
  magnetic concentrations were identified to correspond to bright points
  in G band/CaII H images. From an analysis of time-sliced diagrams, we
  derived the following properties of emerging flux, which are consistent
  with those of previous studies: (1) Two footpoints separate each other
  at a speed of 4.2kms<SUP>-1</SUP> during the initial phase of evolution,
  and decrease to about 1kms<SUP>-1</SUP> 10minutes later. (2) CaII H
  filaments appear almost simultaneously with the formation of dark lanes
  in Stokes I in an observational cadence of 2minutes. (3) The lifetime
  of the dark lanes in the Stokes I and G band is 8minutes, while that
  of Ca filament is 12minutes. An interesting phenomena was observed,
  that an emerging flux tube expanded laterally in the photosphere with a
  speed of 3.8kms<SUP>-1</SUP>. A discussion on the horizontal expansion
  of the flux tube is given with refernce to previous simulation studies.

Title: Observations of Sunspot Oscillations in G Band and CaII H
    Line with Solar Optical Telescope on Hinode
Authors: Nagashima, Kaori; Sekii, Takashi; Kosovichev, Alexander G.;
   Shibahashi, Hiromoto; Tsuneta, Saku; Ichimoto, Kiyoshi; Katsukawa,
   Yukio; Lites, Bruce; Nagata, Shin'ichi; Shimizu, Toshifumi; Shine,
   Richard A.; Suematsu, Yoshinori; Tarbell, Theodore D.; Title, Alan M.
Bibcode: 2007PASJ...59S.631N
Altcode: 2007arXiv0709.0569N
  Exploiting high-resolution observations made by the Solar Optical
  Telescope on board Hinode, we investigate the spatial distribution
  of the power spectral density of the oscillatory signal in and around
  the active region NOAA 10935. The G-band data show that in the umbra
  the oscillatory power is suppressed in all frequency ranges. On
  the other hand, in CaII H intensity maps oscillations in the umbra,
  so-called umbral flashes, are clearly seen with the power peaking around
  5.5mHz. The CaII H power distribution shows the enhanced elements with
  the spatial scale of the umbral flashes over most of the umbra, but
  there is a region with suppressed power at the center of the umbra. The
  origin and property of this node-like feature remain unexplained.

Title: Hinode SP Vector Magnetogram of AR10930 and Its
    Cross-Comparison with MDI
Authors: Moon, Yong-Jae; Kim, Yeon-Han; Park, Young-Deuk; Ichimoto,
   Kiyoshi; Sakurai, Takashi; Chae, Jongchul; Cho, Kyung Suk; Bong,
   Suchan; Suematsu, Yoshinori; Tsuneta, Saku; Katsukawa, Yukio; Shimojo,
   Masumi; Shimizu, Toshifumi; Shine, Richard A.; Tarbell, Theodore D.;
   Title, Alan M.; Lites, Bruce; Kubo, Masahito; Nagata, Shin'ichi;
   Yokoyama, Takaaki
Bibcode: 2007PASJ...59S.625M
Altcode:
  We present one Hinode Spectropolarimeter (SP) magnetogram of AR 10930
  that produced several major flares. The inversion from Stokes profiles
  to magnetic field vectors was made using the standard Milne-Eddington
  code. We successfully applied the Uniform Shear Method for resolving
  the 180° ambiguity to the magnetogram. The inversion gave very strong
  magnetic field strengths (near 4500 gauss) for a small portion of area
  in the umbra. Considering that the observed V-profile of 6301.5Å was
  well-fitted as well as a direct estimation of the Zeeman splitting
  results in 4300-4600 gauss, we think that the field strengths
  should not be far from the actual value. A cross-comparison of the
  Hinode SP and SOHO MDI high resolution flux densities shows that the
  MDI flux density could be significantly underestimated by about a
  factor of two. In addition, it has a serious negative correlation
  (the so-called Zeeman saturation effect) with the Hinode SP flux
  density for umbral regions. Finally, we could successfully obtain
  a recalibrated MDI magnetogram that has been corrected for the
  Zeeman saturation effect using not only a pair of MDI intensity and
  magnetogram data simultaneously observed, but also the relationship
  from the cross-comparison between the Hinode SP and MDI flux densities.

Title: Formation Process of a Light Bridge Revealed with the Hinode
    Solar Optical Telescope
Authors: Katsukawa, Yukio; Yokoyama, Takaaki; Berger, Thomas E.;
   Ichimoto, Kiyoshi; Kubo, Masahito; Lites, Bruce; Nagata, Shin'ichi;
   Shimizu, Toshifumi; Shine, Richard A.; Suematsu, Yoshinori; Tarbell,
   Theodore D.; Title, Alan M.; Tsuneta, Saku
Bibcode: 2007PASJ...59S.577K
Altcode: 2007arXiv0709.2527K
  The Solar Optical Telescope (SOT) on-board Hinode successfully and
  continuously observed the formation process of a light bridge in a
  matured sunspot of the NOAA active region 10923 for several days with
  high spatial resolution. During its formation, many umbral dots were
  observed to be emerging from the leading edges of penumbral filaments,
  and rapidly intruding into the umbra. The precursor of the light bridge
  formation was also identified as a relatively slow inward motion of
  the umbral dots, which emerged not near the penumbra, but inside the
  umbra. The spectro-polarimeter on SOT provided physical conditions in
  the photosphere around the umbral dots and the light bridges. We found
  that the light bridges and the umbral dots had significantly weaker
  magnetic fields associated with upflows relative to the core of the
  umbra, which implies that there was hot gas with weak field strength
  penetrating from the subphotosphere to near the visible surface inside
  those structures. There needs to be a mechanism to drive the inward
  motion of the hot gas along the light bridges. We suggest that the
  emergence and the inward motion are triggered by a buoyant penumbral
  flux tube as well as subphotospheric flow crossing the sunspot.

Title: Umbral Fine Structures in Sunspots Observed with Hinode Solar
    Optical Telescope
Authors: Kitai, Reizaburo; Watanabe, Hiroko; Nakamura, Tahei; Otsuji,
   Ken-ichi; Matsumoto, Takuma; UeNo, Satoru; Nagata, Shin'ichi; Shibata,
   Kazunari; Muller, Richard; Ichimoto, Kiyoshi; Tsuneta, Saku; Suematsu,
   Yoshinori; Katsukawa, Yukio; Shimizu, Toshifumi; Tarbell, Theodore D.;
   Shine, Richard A.; Title, Alan M.; Lites, Bruce
Bibcode: 2007PASJ...59S.585K
Altcode: 2007arXiv0711.3266K
  A high resolution imaging observation of a sunspot umbra was made with
  the Hinode Solar Optical Telescope. Filtergrams at wavelengths of the
  blue and green continua were taken during three consecutive days. The
  umbra consisted of a dark core region, several diffuse components,
  and numerous umbral dots. We derived basic properties of umbral dots
  (UDs), especially their temperatures, lifetimes, proper motions,
  spatial distribution, and morphological evolution. The brightness
  of UDs is confirmed to depend on the brightness of their surrounding
  background. Several UDs show fission and fusion. Thanks to the stable
  condition of the space observation, we could for the first time follow
  the temporal behavior of these events. The derived properties of the
  internal structure of the umbra are discussed from the viewpoint of
  magnetoconvection in a strong magnetic field.

Title: On Connecting the Dynamics of the Chromosphere and Transition
    Region with Hinode SOT and EIS
Authors: Hansteen, Viggo H.; de Pontieu, Bart; Carlsson, Mats;
   McIntosh, Scott; Watanabe, Tetsuya; Warren, Harry P.; Harra, Louise K.;
   Hara, Hirohisa; Tarbell, Theodore D.; Shine, Dick; Title, Alan M.;
   Schrijver, Carolus J.; Tsuneta, Saku; Katsukawa, Yukio; Ichimoto,
   Kiyoshi; Suematsu, Yoshinori; Shimizu, Toshifumi
Bibcode: 2007PASJ...59S.699H
Altcode: 2007arXiv0711.0487H
  We use coordinated Hinode SOT/EIS observations that include
  high-resolution magnetograms, chromospheric, and transition region
  (TR) imaging, and TR/coronal spectra in a first test to study how
  the dynamics of the TR are driven by the highly dynamic photospheric
  magnetic fields and the ubiquitous chromospheric waves. Initial
  analysis shows that these connections are quite subtle and require a
  combination of techniques including magnetic field extrapolations,
  frequency-filtered time-series, and comparisons with synthetic
  chromospheric and TR images from advanced 3D numerical simulations. As a
  first result, we find signatures of magnetic flux emergence as well as
  3 and 5mHz wave power above regions of enhanced photospheric magnetic
  field in both chromospheric, transition region, and coronal emission.

Title: Can High Frequency Acoustic Waves Heat the Quiet Sun
    Chromosphere?
Authors: Carlsson, Mats; Hansteen, Viggo H.; de Pontieu, Bart;
   McIntosh, Scott; Tarbell, Theodore D.; Shine, Dick; Tsuneta, Saku;
   Katsukawa, Yukio; Ichimoto, Kiyoshi; Suematsu, Yoshinori; Shimizu,
   Toshifumi; Nagata, Shin'ichi
Bibcode: 2007PASJ...59S.663C
Altcode: 2007arXiv0709.3462C
  We use Hinode/SOT Ca II H-line and blue continuum broadband observations
  to study the presence and power of high frequency acoustic waves at
  high spatial resolution. We find that there is no dominant power at
  small spatial scales; the integrated power using the full resolution of
  Hinode (0.05'' pixels, 0.16'' resolution) is larger than the power in
  the data degraded to 0.5'' pixels (TRACE pixel size) by only a factor
  of 1.2. At 20 mHz the ratio is 1.6. Combining this result with the
  estimates of the acoustic flux based on TRACE data of Fossum &amp;
  Carlsson (2006), we conclude that the total energy flux in acoustic
  waves of frequency 5-40 mHz entering the internetwork chromosphere of
  the quiet Sun is less than 800 W m$^{-2}$, inadequate to balance the
  radiative losses in a static chromosphere by a factor of five.

Title: Formation of Moving Magnetic Features and Penumbral Magnetic
    Fields with Hinode/SOT
Authors: Kubo, Masahito; Ichimoto, Kiyoshi; Shimizu, Toshifumi;
   Tsuneta, Saku; Suematsu, Yoshinori; Katsukawa, Yukio; Nagata,
   Shin'ichi; Tarbell, Theodore D.; Shine, Richard A.; Title, Alan M.;
   Frank, Zoe A.; Lites, Bruce; Elmore, David
Bibcode: 2007PASJ...59S.607K
Altcode: 2007arXiv0709.1853K
  Vector magnetic fields of moving magnetic features (MMFs) were well
  observed with the Solar Optical Telescope (SOT) aboard the Hinode
  satellite. We focused on the evolution of three MMFs with the SOT in
  this study. We found that an MMF having relatively vertical fields
  with the same polarity as the sunspot was detached from the penumbra
  around the granules appearing in the outer penumbra. This suggests
  that granular motions in the outer penumbra are responsible for
  disintegration of the sunspot. Two MMFs with polarity opposite to
  the sunspot are located around the outer edge of horizontal fields
  extending from the penumbra. This is evidence that the MMFs with
  polarity opposite to the sunspot are the prolongation of penumbral
  horizontal fields. Redshifts larger than the sonic velocity in the
  photosphere are detected for some of the MMFs with polarity opposite
  to the sunspot.

Title: A Tale of Two Spicules: The Impact of Spicules on the Magnetic
    Chromosphere
Authors: de Pontieu, Bart; McIntosh, Scott; Hansteen, Viggo H.;
   Carlsson, Mats; Schrijver, Carolus J.; Tarbell, Theodore D.; Title,
   Alan M.; Shine, Richard A.; Suematsu, Yoshinori; Tsuneta, Saku;
   Katsukawa, Yukio; Ichimoto, Kiyoshi; Shimizu, Toshifumi; Nagata,
   Shin'ichi
Bibcode: 2007PASJ...59S.655D
Altcode: 2007arXiv0710.2934D
  We use high-resolution observations of the Sun in CaIIH (3968Å)
  from the Solar Optical Telescope on Hinode to show that there are
  at least two types of spicules that dominate the structure of the
  magnetic solar chromosphere. Both types are tied to the relentless
  magnetoconvective driving in the photosphere, but have very different
  dynamic properties. ``Type-I'' spicules are driven by shock waves
  that form when global oscillations and convective flows leak into
  the upper atmosphere along magnetic field lines on 3--7minute
  timescales. ``Type-II'' spicules are much more dynamic: they form
  rapidly (in ∼ 10s), are very thin (≤ 200 km wide), have lifetimes
  of 10-150s (at any one height), and seem to be rapidly heated to
  (at least) transition region temperatures, sending material through
  the chromosphere at speeds of order 50--150kms<SUP>-1</SUP>. The
  properties of Type II spicules suggest a formation process that is
  a consequence of magnetic reconnection, typically in the vicinity
  of magnetic flux concentrations in plage and network. Both types of
  spicules are observed to carry Alfvén waves with significant amplitudes
  of order 20kms<SUP>-1</SUP>.

Title: Estimate on SOT Light Level in Flight with Throughput
    Measurements in SOT Sun Tests
Authors: Shimizu, T.; Kubo, M.; Tarbell, T. D.; Berger, T. E.;
   Suematsu, Y.; Ichimoto, K.; Katsukawa, Y.; Miyashita, M.; Noguchi,
   M.; Nakagiri, M.; Tsuneta, S.; Elmore, D. F.; Lites, B. W.
Bibcode: 2007ASPC..369...51S
Altcode:
  The SOT (Solar Optical Telescope, e.g., Shimizu 2004) optical
  system consists of 50cm-aperture optical telescope (OTA) and focal
  plane instrument (FPP). The solar light into the telescope penetrates
  through many optical elements located in OTA and FPP before illuminating
  CCDs. Natural solar light was fed to the integrated SOT in sun tests for
  verifying various optical aspects including the confirmation of photon
  throughput. CCD exposures provide the number of photons accumulated
  in an exposure duration with a clean-room test condition. To estimate
  the absolute intensity of the solar light at the telescope entrance
  in the clean-room test condition, we developed a pinhole-PSD sensor
  for simultaneous monitoring the solar light outside the clean room
  and measured the transmission of light through two flat mirrors of
  the heliostat and clean-room entrance window glass as a function of
  wavelength. The PSD sensor was pre-calibrated with continuous monitoring
  the solar light in a day long under a clear constant sky condition,
  determining the earth atmospheric attenuation and the PSD output for
  the solar light on orbit. These throughput measurements have provided
  an estimate on photon throughput for the SOT flight model. The results
  confirm suitable number of photons without saturation for proper CCD
  exposures in flight.

Title: Performance Characteristics of the Solar-B Spectro-Polarimeter
Authors: Lites, B. W.; Elmore, D. F.; Streander, K. V.; Hoffmann,
   C. M.; Tarbell, T. D.; Title, A. M.; Shine, R. A.; Ichimoto, K.;
   Tsuneta, S.; Shimizu, T.; Suematsu, Y.
Bibcode: 2007ASPC..369...55L
Altcode:
  The Focal Plane Package (FPP) of the Solar Optical Telescope (SOT)
  includes the first precision Spectro-Polarimeter (SP) for solar space
  observations. The FPP/SP will provide high precision measures of
  the vector magnetic field in the solar photosphere. Here we present
  some as-built performance specifications for the entire system of
  telescope + polarimeter. The FPP-SP system represents significant
  gains in several aspects over existing spectro-polarimetric systems;
  notably, angular resolution, polarimetric accuracy, spectral purity,
  and most importantly, temporal continuity of stable, high angular
  resolution. In this short summary of the poster, a few of the
  performance characteristics of the SP are presented.

Title: Calibration of the SOT Polarization
Authors: Ichimoto, K.; Suematsu, Y.; Shimizu, T.; Katsukawa, Y.;
   Noguchi, M.; Nakagiri, M.; Miyashita, M.; Tsuneta, S.; Tarbell, T. D.;
   Shine, R. A.; Hoffmann, C. M.; Cruz, T.; Lites, B. W.; Elmore, D. F.
Bibcode: 2007ASPC..369...39I
Altcode:
  Calibration of SOT polarization property was performed using natural
  sunlight and well calibrated sheet polarizer (linear and circular)
  placed on the entrance of the telescope. The polarimeter response
  matrices were determined for the spectropolarimeter (SP) and the
  narrowband filter imager (NFI), and it is shown that they are well
  behave as predicted and constant over the field of view. The crosstalk
  between I,Q,U,V will be suppressed to the negligible level at the
  photometric accuracy of 10^{-3} after the calibration with the obtained
  matrices. The sensitivity of SOT on linear and circular polarizations
  at each wavelength observed by NFI are also obtained.

Title: Calibration of SOT Dopplergrams
Authors: Katsukawa, Y.; Ichimoto, K.; Sekii, T.; Suematsu, Y.; Tsuneta,
   S.; Shine, R. A.; Tarbell, T. D.
Bibcode: 2007ASPC..369...43K
Altcode:
  Narrow-band Filter Imager on SOT provides Dopplergrams (DGs) which
  are images of Doppler (line- of-sight) velocities. Observations with
  DGs are critically important in studies of photospheric dynamics and
  helioseismology. The primary photospheric line used for DGs is Fe I 5576
  Å which is a line insensitive to Zeeman effect. We made a calibration
  function for the 5576 Å DGs to get actual Doppler velocities from
  velocity indexes using an atlas spectrum and simulated transmission
  profiles for the tunable filter (TF) on SOT. Using data sets taken
  in the natural sun-light test, we quantitatively evaluated accuracy
  of the DGs by comparing the rotational speed of the Sun measured
  with DGs with the expected one. There was a little systematic error
  in the velocity obtained by SOT, but the error was less than 20 %
  of the predicted velocities.

Title: Examinations of the Relative Alignment of the Instruments
    on SOT
Authors: Okamoto, T. J.; Katsukawa, Y.; Shimizu, T.; Ichimoto, K.;
   Suematsu, Y.; Tsuneta, S.; Tarbell, T. D.
Bibcode: 2007ASPC..369...47O
Altcode:
  We report the results of the examination about the relative alignment
  among the instruments on SOT. We employ a test data set obtained in the
  natural sun-light test in May 2005, which has had a grid pattern over
  the entire FOV. SOT has the filtergraph (FG) and the spectro-polarimeter
  (SP). The FG consists of six broadband filter imagers (BFI) and six
  narrowband filter imagers (NFI). We examined the displacements among
  the images taken with different filters to an accuracy of better than
  0.1 pixel corresponding to 0.02''. It is important to know relative
  displacements and plate scales of these instruments for accurate
  alignment of observational data. We note that the values measured in
  our work are relative and it is needed to decide the absolute values
  with another way.

Title: Vector Spectropolarimetry of Dark-cored Penumbral Filaments
    with Hinode
Authors: Bellot Rubio, L. R.; Tsuneta, S.; Ichimoto, K.; Katsukawa,
   Y.; Lites, B. W.; Nagata, S.; Shimizu, T.; Shine, R. A.; Suematsu,
   Y.; Tarbell, T. D.; Title, A. M.; del Toro Iniesta, J. C.
Bibcode: 2007ApJ...668L..91B
Altcode: 2007arXiv0708.2791B
  We present spectropolarimetric measurements of dark-cored penumbral
  filaments taken with Hinode at a resolution of 0.3". Our observations
  demonstrate that dark-cored filaments are more prominent in polarized
  light than in continuum intensity. Far from disk center, the Stokes
  profiles emerging from these structures are very asymmetric and show
  evidence for magnetic fields of different inclinations along the
  line of sight, together with strong Evershed flows of at least 6-7 km
  s<SUP>-1</SUP>. In sunspots closer to disk center, dark-cored penumbral
  filaments exhibit regular Stokes profiles with little asymmetries due
  to the vanishing line-of-sight component of the horizontal Evershed
  flow. An inversion of the observed spectra indicates that the magnetic
  field is weaker and more inclined in the dark cores as compared with
  the surrounding bright structures. This is compatible with the idea
  that dark-cored filaments are the manifestation of flux tubes carrying
  hot Evershed flows.

Title: Emergence of Small-Scale Magnetic Loops in the Quiet-Sun
    Internetwork
Authors: Centeno, R.; Socas-Navarro, H.; Lites, B.; Kubo, M.; Frank,
   Z.; Shine, R.; Tarbell, T.; Title, A.; Ichimoto, K.; Tsuneta, S.;
   Katsukawa, Y.; Suematsu, Y.; Shimizu, T.; Nagata, S.
Bibcode: 2007ApJ...666L.137C
Altcode: 2007arXiv0708.0844C
  We study the emergence of magnetic flux at very small spatial
  scales (less than 2") in the quiet-Sun internetwork. To this aim,
  a time series of spectropolarimetric maps was taken at disk center
  using the instrument SP/SOT on board Hinode. The LTE inversion of
  the full Stokes vector measured in the Fe I 6301 and 6302 Å lines
  allows us to retrieve the magnetic flux and topology in the region
  of study. In the example presented here, the magnetic flux emerges
  within a granular structure. The horizontal magnetic field appears
  prior to any significant amount of vertical field. As time goes on,
  the traces of the horizontal field disappear, while the vertical dipoles
  drift-carried by the plasma motions-toward the surrounding intergranular
  lanes. These events take place within typical granulation timescales.

Title: The Hinode (Solar-B) Mission: An Overview
Authors: Kosugi, T.; Matsuzaki, K.; Sakao, T.; Shimizu, T.; Sone,
   Y.; Tachikawa, S.; Hashimoto, T.; Minesugi, K.; Ohnishi, A.; Yamada,
   T.; Tsuneta, S.; Hara, H.; Ichimoto, K.; Suematsu, Y.; Shimojo, M.;
   Watanabe, T.; Shimada, S.; Davis, J. M.; Hill, L. D.; Owens, J. K.;
   Title, A. M.; Culhane, J. L.; Harra, L. K.; Doschek, G. A.; Golub, L.
Bibcode: 2007SoPh..243....3K
Altcode:
  The Hinode satellite (formerly Solar-B) of the Japan Aerospace
  Exploration Agency's Institute of Space and Astronautical Science
  (ISAS/JAXA) was successfully launched in September 2006. As the
  successor to the Yohkoh mission, it aims to understand how magnetic
  energy gets transferred from the photosphere to the upper atmosphere
  and results in explosive energy releases. Hinode is an observatory
  style mission, with all the instruments being designed and built to
  work together to address the science aims. There are three instruments
  onboard: the Solar Optical Telescope (SOT), the EUV Imaging Spectrometer
  (EIS), and the X-Ray Telescope (XRT). This paper provides an overview
  of the mission, detailing the satellite, the scientific payload, and
  operations. It will conclude with discussions on how the international
  science community can participate in the analysis of the mission data.

Title: Chromospheric Micro-jets Discovered Above Sunspot Penumbrae
Authors: Katsukawa, Yukio; Tsuneta, S.; Suematsu, Y.; Ichimoto, K.;
   Shimizu, T.; Kubo, M.; Nagata, S.; Berger, T.; Tarbell, T.; Shine,
   R.; Title, A.
Bibcode: 2007AAS...210.9413K
Altcode: 2007BAAS...39..219K
  The Solar Optical Telescope (SOT) aboard HINODE allows us to observe
  dynamical activities in the solar photosphere and the chromosphere
  with high and stable image quality of 0.2 arcseconds. This superior
  performance of SOT provides new findings of fine-scale transient
  activities occurring in the chromosphere. In this paper, we report
  discovery of fine-scale jet-like phenomena ubiquitously observed
  above sunspot penumbrae. The jets are identified in image sequences
  of a sunspot taken through a Ca II H line filter at 3968A. The Ca II
  H line is sensitive to about 10^4 K plasma in the chromosphere. <P
  />Their length is typically between 3000 and 10000km, and their
  width is smaller than 500km. It is notable that their lifetime
  is shorter than 1 minute. Those small spatial and temporal scale
  possibly makes it difficult to identify the phenomena in existing
  ground-based observations. The jets are easily identified when a
  sunspot is located far from the disk center, and motion of the bright
  features suggests that mass is erupted from lower chromosphere to upper
  atmosphere. Velocities of the motion are estimated to be 50 to 100 km/s
  from their lateral motion of intensity patterns. The velocities are much
  faster than sound speeds in the chromosphere. A possible cause of such
  high-speed jets is magnetic reconnection at the lower chromosphere
  resulted from fluted magnetic configuration in penumbrae which is
  suggested by vector magnetic field measurements in the photosphere.

Title: Hinode Data Calibration For Precise Image Co-alignment:
    XRT vs. SOT
Authors: Shimizu, Toshifumi; DeLuca, E. E.; Lundquist, L.; Sakao,
   T.; Kubo, M.; Narukage, N.; Kano, R.; Katsukawa, Y.; Ichimoto, K.;
   Suematsu, Y.; Tsuneta, S.; Tarbell, T.; Shine, D.; Hinode Team
Bibcode: 2007AAS...210.9417S
Altcode: 2007BAAS...39Q.220S
  From late October in 2006, Hinode solar optical telescope (SOT) has
  started to produce series of 0.2-0.3 arcsec visible-light images,
  revealing dynamical behaviors of solar magnetic fields on the
  solar surface. Simultaneously, Hinode X-ray telescope (XRT) has been
  providing 1 arcsec resolution X-ray images of the solar corona, giving
  the location of heating and dynamics occuring in the corona. Precise
  image co-alignment of SOT data on XRT data with sub-arcsec accuracy is
  required to provide new information regarding connecting the corona to
  the photosphere. This presentation will give an introduction of Hinode
  between-telescopes' image co-alignment to SPD participants. For active
  region observations with sunspots, sunspots can be used as fiducial to
  co-align the data from the two telescopes each other. Satellite jitter
  in order of 1 arcsec or less is included in the series of XRT data,
  whereas image stabilization system (correlation tracker) removes the
  satellite jitter from the series of SOT images. Telescope pointings show
  orbital variation in order of a few arcsec, which can be well predicted
  from Hinode orbit information. Modeling co-alignment is under study
  and it is the only precise method for quiet Sun and limb observations.

Title: Magnetic Patches in Internetwork Quiet Sun
Authors: De Wijn, Alfred; Lites, B.; Berger, T.; Shine, R.; Title,
   A.; Katsukawa, Y.; Tsuneta, S.; Suematsu, Y.; Shimizu, T.; Hinode Team
Bibcode: 2007AAS...210.9412D
Altcode: 2007BAAS...39Q.219D
  We study strong flux elements in the quiet sun in the context of
  the nature of quiet-sun magnetism, its coupling to chromospheric,
  transition-region and coronal fields, and the nature of a local
  turbulent dynamo. Strong, kilogauss flux elements show up intermittently
  as small bright points in G-band and Ca II H images. Although
  bright points have been extensively studied in the magnetic network,
  internetwork magnetism has only come under scrutiny in recent years. A
  full spectrum of field strengths seems to be ubiquitously present in
  the internetwork at small spatial scales, with the stronger elements
  residing in intergranular lanes. De Wijn et al. (2005) found that bright
  points in quiet sun internetwork areas appear recurrently with varying
  intensity and horizontal motion within long-lived patches that outline
  cell patterns on mesogranular scales. They estimate that the "magnetic
  patches" have a mean lifetime of nine hours, much longer than granular
  timescales. We use multi-hour sequences of G-band and Ca II H images
  as well as magnetograms recorded by the Hinode satellite to follow up
  on their results. The larger field of view, the longer sequences, the
  addition of magnetograms, and the absence of atmospheric seeing allows
  us to better constrain the patch lifetime, to provide much improved
  statistics on IBP lifetime, to compare IBPs to network bright points,
  and to study field polarity of IBPs in patches and between nearby
  patches. <P />Hinode is an international project supported by JAXA,
  NASA, PPARC and ESA. We are grateful to the Hinode team for all their
  efforts in the design, build and operation of the mission.

Title: Hinode/SOT Observations Of Apparent "Thermal Plume" Motions
    In A Solar Prominence
Authors: Berger, Thomas; Tarbell, T.; Slater, G.; Tsuneta, S.;
   Suematsu, Y.; Ichimoto, K.; Katsukawa, Y.; Shimizu, T.; Kubo, M.;
   Nagata, S.
Bibcode: 2007AAS...210.9433B
Altcode: 2007BAAS...39..222B
  We present 396.8 nm Ca II H-line observations of a large
  hedgerow, or "sheet", prominence seen on the solar western limb
  on 30-November-2006. The 16 second cadence observations show dark
  channels rising vertically at speeds of approximately 10 km/sec to
  heights of about 15 Mm above the limb. Many of the motions end in
  vortical overturning near the top of the sheet . Bright downflows of
  similar speed are also seen within the sheet, often in association
  with a dark channel that has risen to the top of the sheet. The dark
  channels are suggestive of hot material rising in thermal plumes
  within the prominence sheet. Similarly, the bright material motions
  appear to be density enhanced regions of turbulent downflow. Current
  models of sheet prominences do not include the observed dynamics. In
  these models, the prominence plasma is in a low-beta state and is
  constrained to move only along magnetic field lines. However the
  motions observed here are extremely complex, implying either that the
  magnetic field lines are undergoing turbulent motion, thus tangling
  and reconnecting constantly, or that the plasma is not constrained
  by the field and is in a high-beta convective state. We measure the
  motion of several representative "plumes" and downflows, estimate the
  density and temperature of the prominence plasma, and suggest several
  avenues for further investigation. <P />This work was supported by
  NASA under the Hinode/SOT contract NNM07AA01C.

Title: High Resolution Observation of Spicules in Ca II H with
    Hinode/SOT
Authors: Suematsu, Yoshinori; Katsukawa, Y.; Ichimoto, K.; Tsuneta, S.;
   Okamoto, T.; Nagata, S.; Shimizu, T.; Tarbell, T.; Shine, R.; Title, A.
Bibcode: 2007AAS...210.9411S
Altcode: 2007BAAS...39..219S
  High cadence observation with a Ca II H broadband filtergraph
  (passband of 0.25 nm) of the Solar Optical Telescope (SOT) aboard
  HINODE has revealed dynamical nature of solar limb spicules. Thanks to a
  diffraction-limited and low-scattered light property of the instrument,
  we can track the detailed evolution of individual spicules for the first
  time with a spatial resolution of 0.2 arcsec. The spicules in Ca II
  H are typically several arcsec tall and have multi-thread structure;
  each threads are a few tenth of arcsec wide. It should be stressed
  that most spicules do not show a simple up-and-down motion along a
  rigid path line. They start with bright structure emanating from Ca II
  H bright region, get widen and diffused with time and ascent, showing
  expansion with lateral or even helical motion in tall events. Small and
  short lived spicules tend to fade out after ascent. We will present
  new findings of spicule dynamics in different magnetic environments
  and discuss about long standing controversy of its motion and evolution.

Title: Hinode/SOT Observation of Fine Structure of the Evershed Flow
Authors: Ichimoto, Kiyoshi; Suematsu, Y.; Tsuneta, S.; Katsukawa, Y.;
   Shimojo, M.; Kubo, M.; Shimizu, T.; Shine, R.; Tarbell, T.; Title,
   A.; Lites, B.; Elmore, D.; Yokoyama, T.; Nagaka, S.
Bibcode: 2007AAS...210.9408I
Altcode: 2007BAAS...39..218I
  Small scale structure of the Evershed effect was studied using the
  Spectropolarimeter (SP) and Broadband Filter Imager (BFI) of SOT aboard
  Hinode. SP maps and high cadence continuum images of BFI coverting
  entire sunspots are used to investigate the spatial distribution of
  the flow field, brightness and magnetic fields. It is revealed that the
  Evershed flow starts at the front edge of inwardly migrating penumbral
  grains with an upward velocity component and turns to nearly holizontal
  flow preferentially in dark lanes (or dark core of filaments) of the
  penumbra. Our results are in general agreement with the well known
  uncombed penumbral concept in which the Evershed flow takes place
  in nearly holizontal field channels. We discovered a number of tiny
  elongated regions in deep photosphere in which there is an obvious
  upward motion of 1-1.5km/s distributing over the penumbra. <P />They
  could be identified as the 'foot points' of the individual Evershed
  flow channels. Cross-correlation among the flow speed, intensity,
  magnetic field strength and inclination, and distribution of string
  down flows in and around the penumbra will also be discussed.

Title: Magnetic Flux Emergence In The Quiet Sun Photosphere
Authors: Centeno, Rebecca; Lites, B.; Socas-Navarro, H.; Frank,
   Z.; Shine, R.; Tarbell, T.; Title, A.; Ichimoto, K.; Tsuneta, S.;
   Katsukawa, Y.; Suematsu, Y.; Kubo, M.; Shimizu, T.
Bibcode: 2007AAS...210.9406C
Altcode: 2007BAAS...39..218C
  We study the emergence of magnetic flux at very small spacial scales
  (less than 1 arcsec) in the quiet Sun internetwork. To this aim, several
  time series of spectropolarimetric maps were taken at disk center using
  the instrument SP/SOT on board Hinode. The LTE inversion of the full
  Stokes vector measured in the Fe I 6301 and 6302 lines will allow us
  to retrieve the magnetic flux and topology in the region of study. We
  find that the magnetic flux emerges typically within the granular
  structures. In many cases, the horizontal magnetic field appears
  prior to any significant amount of vertical field. As time goes on,
  the traces of the horizontal field dissapear while the the vertical
  dipoles drift -carried by the plasma motions- towards the surrounding
  intergranular lanes. Sometimes they stay trapped there for a while
  but they eventually either disappear by disgregation/cancelation
  or agregate to other magnetic field concentrations giving rise to
  larger flux elements. The time scale of these events is of the order
  of 10-20 minutes.

Title: Formation of Moving Magnetic Features and Penumbral Magnetic
    Fields
Authors: Kubo, Masahito; Ichimoto, K.; Shimizu, T.; Tsuneta, S.;
   Suematsu, Y.; Katsukawa, Y.; Nagata, S.; Lites, B. W.; Frank, Z.;
   Tarbell, T. D.; Shine, R. A.; Title, A. M.
Bibcode: 2007AAS...210.9410K
Altcode: 2007BAAS...39..218K
  We investigate the formation process of Moving Magnetic Features
  (MMFs) observed with Hinode/SOT. Moving magnetic features are small
  magnetic elements moving outward in the moat region surrounding
  mature sunspots. We derive vector magnetic fields of MMFs around
  simple sunspots near the disk center. Most of MMFs with polarity
  opposite to the sunspot have large redshift around the penumbral outer
  boundary. We find that some of them have Doppler velocities of about
  10 km/s and such large Doppler motion is observed only in the Stokes
  V profile. The Stokes Q and U profiles in the same pixel do not have
  any significant Doppler motions. Horizontal magnetic fields of the
  penumbra frequently extend to the moat region and the MMFs having
  horizontal fields with polarity same as the sunspot are formed. The
  MMFs with polarity opposite to the sunspot appear around the outer
  edge of the extending penumbral fields. We also find penumbral spines,
  which have more vertical magnetic fields than the surroundings, branch
  off at their outer edge and MMFs having relatively vertical fields
  with polarity same as the sunspot are detached from the outer edge
  of the branch. The branch of penumbral spine is formed when granular
  cells in the moat region go into the penumbra.

Title: Ubiquitous Horizontal Magnetic Fields in the Quiet Solar
    Photosphere as Revealed by HINODE Meaurements
Authors: Lites, Bruce W.; Socas Navarro, H.; Berger, T.; Frank,
   Z.; Shine, R.; Tarbell, T.; Title, A.; Ichimoto, K.; Katsukawa,
   Y.; Tsuneta, S.; Suematsu, Y.; Kubo, M.; Shimizu, T.; Nagata, S.;
   Hinode Team
Bibcode: 2007AAS...210.6303L
Altcode: 2007BAAS...39..171L
  Measurements with the HINODE Spectro-Polarimeter (SP) of the quiet
  Sun allow characterization of the weak, mixed-polarity magnetic
  flux at the highest angular resolution to date (0.3"), and with good
  polarimetric sensitivity(0.025% relative to the continuum). The image
  stabilization of the HINODE spacecraft allows long integrations with
  degradation of the image quality only by the evolution of the solar
  granulation. From the Stokes V profile measurements we find an average
  solar "Apparent Flux Density" of 14 Mx cm-2, with significant Stokes V
  signals at every position on the disk at all times. However, there are
  patches of meso-granular size (5-15") where the flux is very weak. At
  this high sensitivity, transverse fields produce measurable Stokes
  Q,U linear polarization signals over a majority of the area, with
  apparent transverse flux densities in the internetwork significantly
  larger than the corresponding longitudinal flux densities. When viewed
  at the center of the solar disk, the Stokes V signals (longitudinal
  fields) show a preference for occurrence in the intergranular lanes,
  and the Q,U signals occur preferably over the granule interiors,
  but neither association is exclusive. <P />Hinode is an international
  project supported by JAXA, NASA, PPARC and ESA. We are grateful to the
  Hinode team for all their efforts in the design, build and operation
  of the mission.

Title: Attempt to detect Aflven waves with Solar Optical Telescope
    aboard Hinode
Authors: Tsuneta, Saku; Suematsu, Y.; Ichimoto, K.; Katsukawa, Y.;
   Shimizu, T.; Nagata, S.; Orozco Suárez, D.; Lites, B.; Shine, D.;
   Tarbell, T.; Title, A.
Bibcode: 2007AAS...210.9428T
Altcode: 2007BAAS...39..222T
  Flux tube on the sun may carry linear and torsional Alfven waves
  generated by photospheric motion. Photospheric motion of 2 km/s would
  provide magnetic fluctuation of 40G for 1KG tube and for the Alfven
  speed of 50km/s. This may be close to the detection limit of the Stokes
  Q and U signals for flux tubes located in the sun center. However,
  for flux tubes located near the limb, the fluctuation would be seen in
  the Stokes V signal, and can be detectable. <P />We also may be able
  to confirm the 90 degree phase shift between magnetic fluctuation and
  velocity fluctuation, which is easier to observe for flux tubes near
  the limb. Detection of waves would be important in terms of coronal
  heating and solar wind acceleration. An attempt to detect waves along
  flux tubes will be reported.

Title: Discovery Of Cool Cloud-like Structures In The Corona With
    Hinode Solar Optical Telescope
Authors: Okamoto, Takenori; Tsuneta, S.; Katsukawa, Y.; Ichimoto,
   K.; Suematsu, Y.; Shimizu, T.; Nagata, S.; Shibata, K.; Tarbell, T.;
   Shine, R.; Berger, T.; Lites, B.; Myers, D.
Bibcode: 2007AAS...210.9426O
Altcode: 2007BAAS...39..221O
  A solar observation satellite Hinode (Japanese for sun rise) was
  launched in September 2006.Hinode carried 3 advanced solar telescopes,
  visible light telescope, EUV imaging spectrometer, and X-ray telescope
  to simultaneously observe the photosphere, chromosphere, transition
  region, and corona. In the performance verification phase of the Hinode
  spacecraft with its telescopes, we observed an active region AR10921
  near the west limb of the solar disk on November 9 2006. At this point,
  we planned to observe spicules on the limb with a broadband filter
  dedicated to Ca II H line (3968A). Ca II-H emission line (3968A) comes
  from plasma with temperature of approx. 10(4) K, which is much lower
  than the coronal temperature of 10(6-7) K. In addition to spectacular
  spicules, we find a large cloud-like structure located 10,000-20,000
  km above the limb. The cloud has a very complex fine structure with
  dominant horizontal thread-like structure. Some features are moving
  horizontally and also have clear vertical oscillatory motions. The
  periods and amplitudes of these oscillations are 130-250 seconds and
  200-850 km, respectively. The vertical oscillatory motion sometimes
  has a coherence length as long as 16,000 km. We conclude that from
  various observational features this vertical oscillation is a signature
  of Alfven waves propagating along the horizontal magnetic fields. We
  will discuss their origin and implications.

Title: Discovery Of Small-scale Horizontal Magnetic Structures On
    The Solar Photosphere
Authors: Ishikawa, Ryohko; Tsuneta, S.; Suematsu, Y.; Ichimoto, K.;
   Katsukawa, Y.; Nagata, S.; Ishobe, H.; Tarbell, T.; Lites, B. W.;
   Title, A.
Bibcode: 2007AAS...210.9404I
Altcode: 2007BAAS...39..217I
  We discover two different types of episodes on the appearance
  of horizontal magnetic fields with Solar Optical Telescope aboard
  Hinode. <P />The first episode is an emergence of strong thin horizontal
  magnetic fields associated with separating vertical components on
  both ends. Its size is about two granules. We also detect strong area
  asymmetry of the environment Stokes Vprofile for the bout 8 minutes
  before the first emergence of the horizontal component. One of the
  footpoints has very strong downflows (several km/s), while the region
  with strong linear polarization signal has small blue shift, indicating
  an upward-moving horizontal flux. <P />The second episode appears to be
  more ubiquitous. Linear polarization signals appear inside granules (not
  in inter-granules). Their size is smaller than granules, and lifetime
  is longer than several minutes. We will summarize the nature of the
  two types of the horizontal magnetic fluxes, and discuss their origin.

Title: Hinode/SOT Observations of Sunspot Penumbral Dynamics and
    Evolution
Authors: Shine, Richard A.; Hagenaar, M.; Tarbell, T.; Title, A.;
   Lites, B.; Ichimoto, K.; Tsuneta, S.; Katsakawa, Y.; Suematsu, Y.;
   Nagata, S.; Kubo, M.; Shimizu, T.
Bibcode: 2007AAS...210.9407S
Altcode: 2007BAAS...39..218S
  The Solar Optical Telescope (SOT) on the Hinode satellite (launched
  October 2006) has obtained long and nearly continuous time series of
  several large sunspots including those in NOAA AR's 10923, 10925,
  and 10930. Here we use high resolution movies taken primarily with
  the broad band Ca II (396.8nm) and G band (430.5nm) channels and
  magnetograms taken with the 630.2nm narrow band channel to study
  the details and short term evolution of penumbral fine structures
  as well as the long term evolution of the sunspots. We compute flow
  maps and use space/time slices to track motions of Evershed clouds,
  penumbral grains, and visualize oscillations. The data contain examples
  of penumbral formation and disintegration including "orphan" penumbra
  (i.e., penumbra without an obvious umbra). There is also an interesting
  instance of "colliding" penumbra in AR 10930 as two sunspots of opposite
  polarity converged. The zone of apparent shear was associated with
  several flares. <P />This work was supported by NASA contract NNM07AA01C

Title: Optical Performance of the Solar Optical Telescope aboard
    HINODE
Authors: Suematsu, Yoshinori; Ichimoto, K.; Katsukawa, Y.; Otsubo,
   M.; Tsuneta, S.; Nakagiri, M.; Noguchi, M.; Tamura, T.; Kato, Y.;
   Hara, H.; Miyashita, M.; Shimizu, T.; Kubo, M.; Sakamoto, Y.
Bibcode: 2007AAS...210.9402S
Altcode: 2007BAAS...39Q.217S
  The Solar Optical Telescope (SOT) carried by HINODE was designed
  to perform a high-precision polarimetric observation of the Sun
  in visible light spectra with a spatial resolution of 0.2 - 0.3
  arcseconds. The SOT is a sophistcated instrument and consists of two
  separate optical parts; the Optical Telescope Assembly (OTA) which is
  50 cm aperture Gregorian telescope feeding the light into following
  observing instruments which is called the focal plane package (FPP)
  made of two filtergraphs and a spectro-polarimeter. The performance
  of the OTA is important because a spatial resolution and its temporal
  stability is mainly determined by this component. To keep the OTA in
  moderate temperature and optical thermal deformation small, it equipped
  newly designed components such as a heat dump and a secondary field stop
  aluminum mirror with high reflectivity silver coating and a temperature
  low-sensitive apochromatic collimataing lens unit with a UV/IR cut
  coating on the first surface. In addition, the SOT has an active image
  stabilization system consisting of correlation tracker, tip-tilt mirror
  and its controller against satellite pointing jitter. It was confirmed
  that this system freezes residual motion to the 0.01 arcsecond level
  on orbit. The image of sub-arcsecond G-band (430.5 nm) bright points
  clearly indicates that the SOT achieves the diffraction-limit on orbit;
  this is also confirmed using a phase diversity method. In this paper,
  we describe details of the design and on-orbit performance of the OTA.

Title: Magnetic Landscape Of Solar Polar Region With Solar Optical
    Telescope Aboard Hinode
Authors: Tsuneta, Saku; Suematsu, Y.; Ichimoto, K.; Shimizu, T.;
   Katsukawa, Y.; Nagata, S.; Orozco Suárez, D.; Lites, B.; Shine, D.;
   Tarbell, T.; Title, A.
Bibcode: 2007AAS...210.9405T
Altcode: 2007BAAS...39..218T
  Solar polar region is the final destination for remnant magnetic
  fields due to meridional flow and granular diffusion, and is very
  important for the global solar dynamo. Hinode satellite carried out
  high-resolution spectro-polarimetric observations for the Northern
  pole on 2006 November 22 as a part of its performance verification
  program. We find ubiquitous isolated (positive and negative) patches
  in the Stokes V map (i.e. fields horizontal to local surface) all over
  the Arctic circle. The Q (vertical to local surface) map indicates
  scattered vertical flux tubes, which have bipolar feature in the U and
  V maps. This suggests canopy-like structure of the strong isolated flux
  tubes. This will be compared with equatorial landscape with similar
  distance from the sun center. Strong flux tube and weaker ubiquitous
  horizontal fields as represented by Stokes V would have implication
  to the current understanding of the global and local dynamo.

Title: Magnetic Field Diagnostic Capability of Solar-B/SOT:
    Filtergraph Instrument
Authors: Ichimoto, K.; Suematsu, Y.; Shimizu, T.; Katsukawa, Y.;
   Tsuneta, S.; Tarbell, T. D.; Shine, R. A.; Hoffmann, C. M.; Title,
   A. M.; Lites, B. W.; Elmore, D. F.; Streander, K. V.
Bibcode: 2006ASPC..358..189I
Altcode:
  The Narrowband Filter Instrument (NFI) of the Solar Optical Telescope
  onboard Solar-B provides 2D magnetograms/Dopplergrams with a tunable
  Lyot filter (width ∼ 0.1 Å) in 6 selected wavelength bands, and
  spatial sampling of 0.08 arcsec/px. The Zeeman-effect sensitivity of
  NFI and the detection limits of weak magnetic fields are evaluated for
  2 photospheric and 3 chromospheric lines. Magnetic-field retrievability
  from the NFI observables is studied using synthetic Stokes profiles
  of Fe I 5250 Å. We find that, with optimized wavelength sampling at 4
  positions, the inferred magnetic field is sufficiently accurate under
  the hypothesis of constant magnetic field and velocity along the LOS.

Title: The Proper Motion of Sunspot and Its Relation to the Flare
    Onset
Authors: Yatini, C. Y.; Suematsu, Y.
Bibcode: 2006apri.meet...34Y
Altcode:
  No abstract at ADS

Title: Completion of Solar-B/Optical Telescope flight model
Authors: Suematsu, Yoshinori; Ichimoto, Kiyosi; Shimizu, Toshifumi;
   Otsubo, Masashi; Nakagiri, Masao; Noguchi, Motokazu; Tamura, Tomonori;
   Katsukawa, Yukio; Kato, Yoshihiro; Hara, Hirohisa; Miyashita, Masakuni;
   Tsuneta, Saku; Kubo, Masahito; Sakamoto, Yasushi
Bibcode: 2005ARAOJ...7...52S
Altcode:
  No abstract at ADS

Title: Solar-B/Optical Telescope flight model is coming up
Authors: Suematsu, Yoshinori; Ichimoto, Kiyoshi; Shimizu, Toshifumi;
   Otsubo, Masashi; Nakagiri, Masao; Noguchi, Motokazu; Tamura, Tomonori;
   Kato, Yoshihiro; Hara, Hirohisa; Miyashita, Masakuni; Tsuneta, Saku;
   Katsukawa, Yukio; Kubo, Masahito; Sakamoto, Yasushi
Bibcode: 2005naoj.book....4S
Altcode:
  No abstract at ADS

Title: New clean room for space instrumentation
Authors: Noguchi, Motokazu; Nakagiri, Masao; Suematsu, Yoshinori;
   Tsuneta, Saku; Kubo, Masahito
Bibcode: 2005naoj.book...37N
Altcode:
  No abstract at ADS

Title: The first build-up of the Solar-B flight models
Authors: Hara, Hirohisa; Ichimoto, Kiyoshi; Otsubo, Masashi; Katsukawa,
   Yukio; Kato, Yoshihiro; Kano, Ryohei; Kumagai, Kazuyoshi; Shibasaki,
   Kiyoto; Shimizu, Toshifumi; Shimojo, Masumi; Suematsu, Yoshinori;
   Tamura, Tomonori; Tsuneta, Saku; Noguchi, Motokazu; Nakagiri, Masao;
   Miyashita, Masakuni; Watanabe, Tesuya; Kosuchi, Takeo; Sakao, Taro;
   Matsuzaki, Keiichi; Kitakoshi, Yasunori; Kubo, Masahito; Sakamoto,
   Yasushi
Bibcode: 2005ARAOJ...7...46H
Altcode:
  No abstract at ADS

Title: Asymmetric Stokes-V Profiles at the Penumbral Boundary of
    a Sunspot
Authors: Choudhary, D. P.; Balasubramaniam, K. S.; Suematsu, Y.
Bibcode: 2004ASPC..325..137C
Altcode:
  We present the spectropolarimetric measurements of a sunspot
  situated near central meridian disk passage. The sunspot was of
  positive polarity with several opposite polarity magnetic elements
  at and beyond the penumbral boundary. The Hα images of the sunspot
  show bright emission regions near the penumbral boundary towards the
  sun-center, which was of opposite polarity to the main spot. Doppler
  velocities determined by measuring the center-of-gravity (COG) of the
  Stokes-I profile, in general, agree with Evershed flow. In addition,
  it shows strong flows in the penumbra. The velocities derived from
  zero-crossing wavelengths of Stokes-V profiles show strong downflows
  at the penumbral boundary. Double-lobed Stokes-V profiles are observed
  at locations where penumbral fibrils terminate coinciding with Hα
  plages. Double lobed profiles have an unshifted component similar to
  the Stokes-V profiles of the sunspot penumbra and a shifted component
  with a velocity of about 5 kmps. The amplitude of the second component
  increases along the penumbral fibril as a function of the distance from
  the center of the sunspot. In this paper we present the preliminary
  results and propose to observe with the SolarB Solar Optical Telescope
  (SOT) for understanding the nature of emerging flux near the sunspots.

Title: Image stabilization system on SOLAR-B Solar Optical Telescope
Authors: Shimizu, Toshifumi; Nagata, Shin'ichi; Edwards, Chris;
   Tarbell, Theodore; Kashiwagi, Yasuhiro; Kodeki, Kazuhide; Ito,
   Osamu; Miyagawa, Hiroyuki; Nagase, Masayuki; Inoue, Syunsaku; Kaneko,
   Kazumasa; Sakamoto, Yasushi; Ichimoto, Kiyoshi; Tsuneta, Saku; Miki,
   Shiro; Endo, Makoto; Tabata, Masaki; Nakaoji, Toshitaka; Matsuzaki,
   Keiichi; Kobayashi, Ken; Otsubo, Masashi; Suematsu, Yoshinori; Kumagai,
   Kazuyoshi; Noguchi, Motokazu; Tamura, Tomonori; Nakagiri, Masao
Bibcode: 2004SPIE.5487.1199S
Altcode:
  Extremely stable pointing of the telescope is required for images on the
  CCD cameras to accurately measure the nature of magnetic field on the
  sun. An image stabilization system is installed to the Solar Optical
  Telescope onboard SOLAR-B, which stabilizes images on the focal plane
  CCD detectors in the frequency range lower than about 20Hz. The system
  consists of a correlation tracker and a piezo-based tip-tilt mirror with
  servo control electronics. The correlation tracker is a high speed CCD
  camera with a correlation algorithm on the flight computer, producing
  a pointing error from series of solar granule images. Servo control
  electronics drives three piezo actuators in the tip-tilt mirror. A
  unique function in the servo control electronics can put sine wave
  form signals in the servo loop, allowing us to diagnose the transfer
  function of the servo loop even on orbit. The image stabilization
  system has been jointly developed by collaboration of National
  Astronomical Observatory of Japan/Mitsubishi Electronic Corp. and
  Lockheed Martin Advanced Technology Center Solar and Astrophysics
  Laboratory. Flight model was fabricated in summer 2003, and we measured
  the system performance of the flight model on a laboratory environment
  in September 2003, confirming that the servo stability within 0-20 Hz
  bandwidth is 0.001-0.002 arcsec rms level on the sun.

Title: The Solar Optical Telescope onboard the Solar-B
Authors: Ichimoto, Kiyoshi; Tsuneta, Saku; Suematsu, Yoshinori;
   Shimizu, Toshifumi; Otsubo, Masashi; Kato, Yoshihiro; Noguchi,
   Motokazu; Nakagiri, Masao; Tamura, Tomonori; Katsukawa, Yukio; Kubo,
   Masahito; Sakamoto, Yasushi; Hara, Hirohisa; Minesugi, Kenji; Ohnishi,
   Akira; Saito, Hideo; Kawaguchi, Noboru; Matsushita, Tadashi; Nakaoji,
   Toshitaka; Nagae, Kazuhiro; Sakamoto, Joji; Hasuyama, Yoshihiro;
   Mikami, Izumi; Miyawaki, Keizo; Sakurai, Yasushi; Kaido, Nobuaki;
   Horiuchi, Toshihida; Shimada, Sadanori; Inoue, Toshio; Mitsutake,
   Masaaki; Yoshida, Norimasa; Takahara, Osamu; Takeyama, Norihide;
   Suzuki, Masaharu; Abe, Shunichi
Bibcode: 2004SPIE.5487.1142I
Altcode:
  The solar optical telescope onboard the Solar-B is aimed to perform a
  high precision polarization measurements of the solar spectral lines
  in visible wavelengths to obtain, for the first time, continuous
  sets of high spatial resolution (~0.2arcsec) and high accuracy
  vector-magnetic-field map of the sun for studying the mechanisms
  driving the fascinating activity phenomena occurring in the solar
  atmosphere. The optical telescope assembly (OTA) is a diffraction
  limited, aplanatic Gregorian telescope with an aperture of Φ500mm. With
  a collimating lens unit and an active folding mirror, the OTA provides
  a pointing-stabilized parallel beam to the focal plane package (FPP)
  with a field of view of about 360x200arcsec. In this paper we identify
  the key technical issues of OTA for achieving the mission goal and
  describe the basic concepts in its optical, mechanical and thermal
  designs. The strategy to verify the in-orbit performance of the
  telescope is also discussed.

Title: Spectroscopic studies of the solar corona using Fe X, XIII,
    XIV lines
Authors: Singh, Jagdev; Sakurai, Takashi; Ichimoto, Kiyoshi; Suematsu,
   Yoshinori; Takeda, Aki
Bibcode: 2004naoj.book...46S
Altcode:
  No abstract at ADS

Title: Thermo-optical testing of the solar optical telescope of
    the Solar-B
Authors: Ichimoto, Kiyoshi; Nakagiri, Masao; Suematsu, Yoshinori;
   Tamura, Tomonori; Tsuneta, Saku; Noguchi, Motokazu; Kato, Yoshihiro;
   Otsubo, Seiji; Katsukawa, Yukio; Kubo, Masahito
Bibcode: 2004naoj.book....6I
Altcode:
  No abstract at ADS

Title: The source of magnetic field twist in solar active regions
Authors: Bao, Shudong; Sakurai, Takashi; Suematsu, Yoshinori
Bibcode: 2004naoj.book...48B
Altcode:
  No abstract at ADS

Title: Solar-B: Status of Project
Authors: Suematsu, Y.
Bibcode: 2003ASPC..289...37S
Altcode: 2003aprm.conf...37S
  The Solar-B spacecraft, currently under development for a planned
  launch in the summer of 2005, carries the Solar Optical Telescope
  (SOT) to make precise measurements of magnetic fields of the solar
  photosphere with a high spatial resolution, the X-Ray Telescope
  (XRT) to observe the dynamics of the high temperature corona, and
  the EUV Imaging Spectrometer (EIS) to observe plasma motions in the
  transition region and corona. The aim of Solar-B is to investigate
  the physical coupling between the photosphere (engine) and the corona
  (dissipater) to ultimately understand the mechanism of coronal dynamics
  and heating. The magnetic field maps with 0.2-0.3 arcsecond resolution,
  the images of the high temperature corona with 1arcsec resolution,
  and the precise coronal velocity maps provided by these telescopes
  will all be new, and unprecedented scientific outcomes are expected.

Title: Development of the Solar-B spacecraft
Authors: Tsuneta, Saku; Ichimoto, Kiyoshi; Suematsu, Yoshinori;
   Shimizu, Toshifumi; Hara, Hirohisa; Kano, Ryohei; Nagata, Shin'ichi;
   Tamura, Tomonori; Nakagiri, Masao; Noguchi, Motokazu; Kato, Yoshihiro;
   Watanabe, Tetsuya; Hanaoka, Yoichiro; Sawa, Masaki; Otsubo, Masashi;
   Kosugi, Takeo; Yamada, Takahiro; Sakao, Taro; Matsuzaki, Keiichi;
   Minesugi, Kenji; Onishi, Akira; Katsukawa, Yukio; Kobayashi, Ken;
   Kubo, Masahito
Bibcode: 2003naoj.book....3T
Altcode:
  No abstract at ADS

Title: Development of Solar-B solar optical telescope
Authors: Suematsu, Yoshinori; Ichimoto, Kiyoshi; Shimizu, Toshifumi;
   Nagata, Shin'ichi; Tamura, Tomonori; Tsuneta, Saku; Noguchi, Motokazu;
   Kato, Yoshihiro; Nakagiri, Masao; Otsubo, Masashi; Hanaoka, Yoichiro;
   Katsukawa, Yukio; Kobayashi, Ken; Kubo, Masahito
Bibcode: 2003naoj.book....5S
Altcode:
  No abstract at ADS

Title: Observational Study of the Three-Dimensional Magnetic Field
    Structure and Mass Motion in Active Regions
Authors: Choudhary, Debi Prasad; Suematsu, Yoshinori; Ichimoto, Kiyoshi
Bibcode: 2002SoPh..209..349C
Altcode:
  Spectro-polarimetric observations of active regions were carried
  out in the spectral lines of Si i 10827.1 Å and He i 10830 Å to
  study the three-dimensional magnetic field structure and associated
  plasma flow properties. Comparison of Si i and He i magnetograms
  with the potential field model shows that a large fraction of the
  magnetic field is consistent with the potential field structure,
  by assuming that the height difference between the origin of the two
  lines is about 1200 km. The slope of the scatter plot between Si i
  and He i magnetograms is 0.5, 0.76 in an emerging flux and a larger
  active region, respectively. These values are lower than the scatter
  plot slopes obtained from Kitt Peak photospheric and chromospheric
  magnetograms, in which case the corresponding values are 0.83 and 0.9,
  respectively. Considering the height difference between these two sets
  of chromospheric magnetograms, this implies that the magnetic field
  spreads out faster near the transition region heights. Dopplergrams
  obtained by determining the centroid of the asymmetric line profiles
  show that, in case of emerging flux region, the chromospheric upflow
  regions are located in the magnetic neutral line areas.

Title: Spectroscopic Studies of the Solar Corona II. Properties of
    Green and Red Emission Lines in Open and Closed Coronal Structures
Authors: Singh, Jagdev; Sakurai, Takashi; Ichimoto, Kiyoshi; Suematsu,
   Yoshinori; Takeda, Aki
Bibcode: 2002PASJ...54..793S
Altcode:
  We obtained profiles of the green (Fe &lt;FONT SIZE="-2"&gt;XIV
  5303Å) and red (Fe &lt;FONT SIZE="-2"&gt;X 6374Å) emission lines
  simultaneously on 1998 July18-19 for about 4hours with a cadence
  of 10minutes, covering an area of about 200'' × 500'' in the
  solar corona. The line width (FWHM), intensity, and Doppler shift
  for both lines were computed using Gaussian fits to the observed
  line profiles. We then studied any systematic differences in these
  parameters between closed and open field structures, and their time
  variations. The derived line widths indicate that the FWHM of the red
  line increases with height above the limb at a rate of 0.5 - 2.6 mÅ
  arcsec<SUP>-1</SUP> and the green-line width decreases with height
  at a rate of 1.2 - 3.4 mÅ arcsec<SUP>-1</SUP>. The difference in
  the time-averaged values of the widths of the green line in open and
  closed coronal structures at a given height above the limb is small,
  whereas the width of the red line in open structures is substantially
  larger than that in the closed loop-like coronal structures.

Title: The Sources of Magnetic Field Twist in Solar Active Regions
Authors: Bao, S. D.; Sakurai, T.; Suematsu, Y.
Bibcode: 2002ApJ...573..445B
Altcode:
  Observations have revealed that a hemispheric preference of magnetic
  chirality (handedness) exists throughout the solar atmosphere. For
  example, the current helicity of active regions is predominantly
  negative (left-handed twist) in the northern hemisphere and
  positive (right-handed twist) in the southern. The explanation
  of this hemispheric tendency is still open to question. In this
  paper we first review several possible mechanisms and clarify some
  misunderstandings. In our views, in the photosphere, the differential
  rotation acting on already emerged sunspot magnetic fields will lead to
  negative current helicity in the northern hemisphere and positive in the
  southern, but the same effect caused by the Coriolis force is opposite
  in sign. In the turbulent convection zone, the Coriolis force acting on
  the rising magnetic flux tubes will result in negative/positive helicity
  in the northern/southern hemisphere, but the corresponding action by the
  differential rotation will give rise to a reversed result. Moreover,
  in this region the α-effect will produce the wrong sign to explain
  the observed sense of magnetic twist. It should be noteworthy that
  the two current helicities generated by the α-effect, that in the
  mean field and that in the fluctuations, have opposite signs, and the
  former is positive/negative in the northern/southern hemisphere while
  the latter is negative/positive in the northern/southern hemisphere. In
  the overshoot region at the base of the convection zone, the current
  helicity created by the α-effect has the sign needed. Finally,
  we suggest that some surface flows (e.g., converging flows that can
  lead to cancellation of opposite-polarity flux in the photosphere)
  and magnetic reconnection are also important to the redistribution
  (or regeneration) of magnetic twist in active regions.

Title: Observational studies of the solar cycle at the National
    Astronomical Observatory of Japan
Authors: Sakurai, T.; Suematsu, Y.
Bibcode: 2002AdSpR..29.1565S
Altcode:
  Instrumentation for observational studies of the solar activity cycle,
  using ground-based optical telescopes at the National Astronomical
  Observatory of Japan, is described. A newly-built 10-cm telescope for
  sunspot observations is explained in detail. A future instrumentation
  plan for long-term studies of the sun, called the Solar Cycle Telescope,
  is presented. This will be composed of a 30-cm Makustov telescope
  equipped with an infrared Stokes polarimeter, and a 15-cm refractor
  for precise Doppler-shift measurements.

Title: Commission 12: Solar Radiation and Structure (Radiation et
    Structure Solaires)
Authors: Foukal, Peter; Solanki, Sami; Mariska, J.; Baliunas, S.;
   Dravins, D.; Duvall, T.; Fang, C.; Gaizauskas, V.; Heinzel, P.;
   Kononovich, E.; Koutchmy, S.; Melrose, D.; Stix, M.; Suematsu, Y.;
   Deubner, F.
Bibcode: 2000IAUTA..24...73F
Altcode:
  No abstract at ADS

Title: Development of New Solar Optical Observation Systems at
    Mitaka, NAOJ
Authors: Suematsu, Y.
Bibcode: 1999spro.proc..443S
Altcode:
  We briefly describe three optical observation systems of the Sun being
  developed at Mitaka, NAOJ.

Title: Derivation of the correction coefficient k in the relative
    sunspot number for a new sunspot observing system at Mitaka.
Authors: Miyashita, M.; Suematsu, Y.; Irie, M.
Bibcode: 1999RNAOJ...4..149M
Altcode:
  A new sunspot observing system using a CCD of 2k×2k pixels has started
  at Mitaka, since April 1998. To determine the personal correction
  coefficient k in the formula for the relative sunspot number, the
  authors compared the sunspot numbers from the new system with those
  from conventional hand-drawing observations at their observatory and
  from S.I.D.C. (Sunspot Index Data Center). As a result, they obtained
  k = 1.0 on the average for the new system. There were, however, some
  cases in which the k-value largely deviates from the average.

Title: Simultaneous 2-D Spatial Spectra Using a Microlens Array
Authors: Balasubramaniam, K. S.; Suematsu, Y.; Smaldone, L. A.;
   Yoshimura, K.; Hegwer, S.; Otani, H.
Bibcode: 1999AAS...194.9306B
Altcode: 1999BAAS...31R.989B
  Simultaneous spatial spectra of extended solar structures, at a high
  spatial resolution and temporal cadence is important to track and
  understand the physics of dynamical evolutionary phenomena. Replacing
  the slit of a conventional spectrograph with a micro-lens array will
  then help to capture simultaneous spatial spectra using a large format
  CCD camera. Such a technique will be useful to study small structures
  (a few arcseconds across) such as Ellerman bombs, kernels of flares,
  filamentary evolution and spicules. At the NSO/Richard B. Dunn Solar
  Telescope, we have used a micro-lens array (0.6 mm pitch, 50 x 50
  lens-lets) to observe structures with a spatial sampling of 0.24
  arcseconds in Hα \ spectral line. The spectral sampling is 0.93
  Angstroms/pixel over a 10- Angstroms bandwidth. The field-of-view
  is however limited to about 12 arcseconds. We have also explored the
  microlens array the observations to magnetic spectral lines such as
  FeI 6301.5 and FeI 6302.5 Angstroms for variation of line-of-sight
  of subarcsecond magnetic fields. We present initial results from an
  engineering observational experiment at the Dunn Solar Telescope.

Title: Characteristic curves of photographic data made with a film
    scanner.
Authors: Iizuka, Y.; Yamasaki, T.; Suematsu, Y.
Bibcode: 1999RNAOJ...4..107I
Altcode: 1999RNOAJ...4..107I
  Thanks to the development of CCD camera and digital technologies,
  photographic observations in astronomy has been getting less
  popular and hence facilities to analyze the photographic data such as
  micro-densitometers are disappearing. Instead, a film scanning device
  with a linear CCD array (a film scanner), which can be controlled by
  a personal computer, becomes available and much more popular for a
  personal use. Hence, it is worth while examining the digitization
  accuracy of the commercial-based film scanner and seeking the
  possibility to replace the micro-densitometer with it. The authors
  found that the film scanner gives good accuracy in comparison with
  the micro-densitometer if the data are handled properly. They describe
  the method and technique how to calibrate photographic data using the
  film scanner.

Title: Scientific Objectives and Design Concepts of the Optical
    Telescope and its Observing Instruments aboard Solar-B
Authors: Suematsu, Y.; Solar-B Working Group
Bibcode: 1999ASPC..183..198S
Altcode: 1999hrsp.conf..198S
  No abstract at ADS

Title: Tridimensional Spectroscopic Observations of the Sun with a
    Microlens-Array Spectrograph
Authors: Suematsu, Y.; Imai, H.; Yoshimura, K.; Ishigaki, T.; Ueno,
   S.; Hayashi, T.; Ohtani, H.
Bibcode: 1999ASPC..183..303S
Altcode: 1999hrsp.conf..303S
  No abstract at ADS

Title: Development of automatic detection and reduction system for
    sunspots and faculae.
Authors: Imai, H.; Suematsu, Y.; Miyashita, M.; Kumagai, K.
Bibcode: 1998RNAOJ...4....1I
Altcode: 1998RNOAJ...4....1I
  The authors describe an acquisition and data processing system
  of full-disk digitial solar images at the National Astronomical
  Observatory. The system aimes at an automated detection and
  data reduction of sunspots and faculae, and will replace the
  conventional hand drawing observation being continued since 1930's
  at the observatory. Full-disk digital images of the sun are taken
  and processed daily to provide automatic drawings of sunspots and
  faculae. The number and parameters of sunspots such as the position,
  area, and darkness are also derived. Data processing techniques used
  for the images are briefly described, which include the method of limb
  fitting, the production of solar contrast map by limb-darkening removal,
  and the detection of sunspots and faculae.

Title: Radiation testing of optical glasses and crystals for Solar-B
    optical instruments.
Authors: Nishino, Y.; Suematsu, Y.; Tsuneta, S.; Ichimoto, K.; Kobiki,
   T.; Takeyama, N.
Bibcode: 1998RNAOJ...3..145N
Altcode: 1998RNOAJ...3..145N
  This report gives some results of γ-ray irradiation (Co<SUP>60</SUP>
  source) testing on optical glasses and crystals which may be used
  in the next Japanese solar space mission Solar-B. Ordinary optical
  glasses darken when exposed to high-energy radiation which is present
  in natural space environment. In case of Solar-B, whose orbit will be
  polar-sun-synchronous, the satellite will undergo the total dose of
  more than 1000 krad in five years. Hence it is very crucial for the
  success of the mission to know the feasibility of transmitting optical
  elements in space. The authors tested two kinds of fused silica, a
  fluorite, and ten kinds of UV transmitting glasses. Calcite was also
  tested. It was found that the fused silica is radiation-resistant but
  the other glasses and the fluorite are nonresistant and become quite
  opaque in UV and visible wavelength regions after the irradiation.

Title: Solar Spicules: A brief review of recent high-resolution
    observations
Authors: Suematsu, Y.
Bibcode: 1998ESASP.421...19S
Altcode: 1998sjcp.conf...19S
  No abstract at ADS

Title: Properties of Hα spicules from disk and limb high-resolution
    observations
Authors: Dara, H. C.; Koutchmy, S.; Suematsu, Y.
Bibcode: 1998ESASP.421..255D
Altcode: 1998sjcp.conf..255D
  No abstract at ADS

Title: SXR Coronal Polar Jets and Recurrent Flashes
Authors: Koutchmy, S.; Hara, H.; Shibata, K.; Suematsu, Y.; Reardon, K.
Bibcode: 1998ASSL..229...87K
Altcode: 1998opaf.conf...87K
  No abstract at ADS

Title: Horseshoe Shaped Hα Solar Flares on 13 Oct 1995 and Emerging
    Flux Model of Flares
Authors: Suematsu, Y.; Nishino, Y.; Yan, Y.; Sato, J.
Bibcode: 1998ASSL..229..209S
Altcode: 1998opaf.conf..209S
  No abstract at ADS

Title: On the correlation between line width and line depth of the
    solar HeI 1083 NM line
Authors: Venkatakrishnan, P.; Sakurai, T.; Suematsu, Y.; Ichimoto, K.
Bibcode: 1997BASI...25..527V
Altcode:
  No abstract at ADS

Title: SXR Coronal Flashes.
Authors: Koutchmy, S.; Hara, H.; Suematsu, Y.; Reardon, K.
Bibcode: 1997A&A...320L..33K
Altcode:
  We provide evidence for the existence of a new type of soft X-ray
  (SXR) brightening event that we call coronal flashes. The phenomenon
  was observed on deep time series taken with the SXT of Yohkoh in the
  north polar coronal hole, near the sunspot minimum. Events last as
  short as 1.5 mn and the corresponding SXR flux span the range of
  energies, from single pixel brightenings corresponding to fluxes
  of about 10^24^erg but barely surpassing the level of the noise,
  to higher and more smeared multiple px brightenings still orders
  of magnitude smaller than the known small SXR bright points and/or
  transient brightenings. The typical occurrence rate of flashes is
  1-event/arcmin^2^/5mn with a 1/2mn integration time. At least part of
  the coronal flashes are recurrent and some of them could be associated
  with a SXR jet; it is not clear what is their optical counterpart.

Title: Spectroscopic Observation of the Solar Active Regions in Hel
    10830 A Line
Authors: Tohmura, Ichirah; Kitai, Reizaburo; Suematsu, Yoshinori;
   Soltau, Dirk
Bibcode: 1996JKASS..29..333T
Altcode:
  No abstract at ADS

Title: Coordinated SPDE rocket, YOHKOH and ground observations of
    an emerging flux region and a filament
Authors: Damé, L.; Martic, M.; Brown, W. A.; Bruner, M. E.; Strong,
   K.; Suematsu, Y.; Tsuneta, S.; Schmieder, B.
Bibcode: 1996AdSpR..17d.189D
Altcode: 1996AdSpR..17..189D
  During the first flight of the Solar Plasma Diagnostic Experiment
  (SPDE), May 12, 1992, we obtained UV filtergrams at high resolution
  (full Sun 0.82'' spatial resolution in the 160 nm continuum, the
  CIV lines and Lyman alpha) with the Ultraviolet Filtergrap Camera
  (UVFC). Closely coordinated observations were obtained with the Soft
  X-ray Telescope (SXT) of the Yohkoh satellite and from dedicated ground
  programs in particular at Sacramento Peak, La Palma and Pic-du-Midi
  observatories. With this unique set of data we cover the solar
  atmosphere as a whole, from the temperature minimum to the high corona
  with essential steps in the chromosphere and transition region. After
  the necessary calibrations of the data set, we present the first results
  of the multitemperature development of an emerging flux region and of
  a filament that rapidly changed right during the rocket short lifetime.

Title: Enhanced He{I} Absorption at the Feet of Solar X-Ray Loops
Authors: Venkatakrishnan, P.; Sakurai, Takashi; Suematsu, Yoshinori;
   Ichimoto, Kiyoshi
Bibcode: 1996PASJ...48L...1V
Altcode:
  A comparison of He{I} spectroheliograms and Yohkoh soft X-ray images
  of active regions indicates that He{I} absorption is enhanced at
  the feet of hot X-ray loops. It is suggested that the conduction of
  heat from the loops into the transition region at their feet would
  produce enhanced transition-region emission around 50 eV that would
  in turn cause enhanced excitation of He{I} leading to the excess He{I}
  absorption that is observed.

Title: High Resolution Observation of Solar Spicules and Their
    Kinematic Modelling
Authors: Suematsu, Y.
Bibcode: 1996mpsa.conf..439S
Altcode: 1996IAUCo.153..439S
  No abstract at ADS

Title: Statistical Studies of Solar H alpha Brightening Events and
    Their Relation to Soft X-ray Events
Authors: Yatini, C. Y.; Suematsu, Y.
Bibcode: 1996mpsa.conf..453Y
Altcode: 1996IAUCo.153..453Y
  No abstract at ADS

Title: He I 10830 Angstroms in Solar Active Regions and its
    Correlation with Chromospheric Lines
Authors: Kitai, R.; Tohmura, I.; Suematsu, Y.; Akioka, M.; Soltau, D.
Bibcode: 1996mpsa.conf..435K
Altcode: 1996IAUCo.153..435K
  No abstract at ADS

Title: High-Resolution Observation of Disk Spicules. I. Evolution
    and Kinematics of Spicules in the Enhanced Network
Authors: Suematsu, Yoshinori; Wang, Haimin; Zirin, Harold
Bibcode: 1995ApJ...450..411S
Altcode:
  We present measurements of a 75 minute sequence of CCD spicule
  observations at Hα -0.65 Å, line center, and +0.65 Å. The
  observations were made in a region of enhanced network near disk
  center, where most spicules are longer and tilted further from the
  vertical than those in truly quiet Sun. Images were reregistered with
  a correlation coefficient greater than 0.9. We identify the spicules
  as those elongated jets that radiate from elements of the magnetic
  network and are the main chromospheric features seen in the wing of
  Hα. Doppler images produced by red-blue subtraction show an upward
  radial velocity during the extension phase and a downward velocity
  during contraction for most spicules. Therefore, the spicules are
  truly moving up and down. There were a few plagelike cells filled
  with weak Hα emission, weak magnetic fields, and no spicules. We
  also found many multiple spicules. The data are presented with
  commentary on the accompanying videotape. <P />We analyzed the
  data to understand the spicule lifetimes and trajectories. We found
  that the entire set of wavelengths and Dopplergrams was required to
  separate overlapping spicules. Seventy-six of the 96 spicules studied
  appear in complete upward and downward trajectories The evidence on
  motions is not conclusive. Some proper motions are well represented
  by ballistic trajectories with initial injection velocity about 40 km
  s<SUP>-1</SUP> for highly inclined spicules. The small decelerations
  would require the spicules to be tilted typically 60°-70° from
  the line of sight. Since limb observations favor tilts around 30°,
  our observations must favor spicules tilted greatly from the radial,
  as one finds in these enhanced field regions. The positive correlation
  of lifetimes with projected lengths supports this model. However, the
  Dopplergrams show that the entire spicule rises and falls as a whole,
  which favors a fountain jet or some acceleration in the flux tube. The
  downward trajectory may be slightly offset toward the network center
  from the upward path. <P />Bright points often appear at the bases of
  spicules at Hα -0.65 Å, but during the peak extension or receding
  phase of the spicule rather than the beginning; therefore, the spicule
  is not a surgelike phenomenon (surges are usually initiated by Hα
  brightening or a subflare, invariably in a bipolar feature). Further,
  the magnetic elements, which match the Hα bright points exactly,
  show no change associated with the brightening. The geometry creates
  a problem for coronal heating models, as the spicule tops are at least
  10" displaced from the bright-point bases, but no such offset appears
  in the K line, for example. There is some evidence that the spicule
  is generated several hundred kilometers above the photosphere.

Title: He I λ1083nm Observations and Chromospheric and Coronal
    Activities
Authors: Suematsu, Y.; Ichimoto, K.; Sakurai, T.
Bibcode: 1995itsa.conf..413S
Altcode:
  No abstract at ADS

Title: Peculiar magnetic field evolution of active region NOAA 7562
    in August 1993 - results from campaign observation with Yohkoh
Authors: Sakurai, T.; Suematsu, Y.; Ichimoto, K.; Kurokawa, H.; Kitai,
   R.; Akioka, M.; Tohmura, I.; Soltau, D.; Mickey, D. L.; Zhang, H.;
   Li, W.; Zirin, H.; Tang, F.
Bibcode: 1994ESASP.373..337S
Altcode: 1994soho....3..337S
  No abstract at ADS

Title: XV NSO/Sac Peak Solar workshop
Authors: Suematsu, Y.
Bibcode: 1994suns.work...19S
Altcode:
  We present some results on studies of line profile fitting analysis
  of He I 1083-nm line spectra which were obtained with a 25-cm aperture
  coronagraph at the Norikura Solar Observatory.

Title: A Very Small Two-Ribbon Flare of GOES X-ray Class B6.7
Authors: Suematsu, Y.
Bibcode: 1994kofu.symp..135S
Altcode:
  No abstract at ADS

Title: Small-Scale Brightening Events Found with Mitaka Hα Patrol
    System and Their Soft X-Ray Signatures from YOHKOH SXT
Authors: Suematsu, Y.; Shimizu, T.; Tanaka, N.
Bibcode: 1994xspy.conf...39S
Altcode:
  No abstract at ADS

Title: On the Coronal and Prominence Structures Observed at the
    Total Solar Eclipse of 11 July 1991
Authors: Suematsu, Y.; Fukushima, H.; Nishino, Y.
Bibcode: 1994IAUS..154..205S
Altcode:
  No abstract at ADS

Title: Small-Scale Brightening Events in H alpha and Soft X-rays in
    Active Regions
Authors: Suematsu, Yoshinori
Bibcode: 1994ASPC...68..412S
Altcode: 1994sare.conf..412S
  No abstract at ADS

Title: Improvement of camera mechanism for Hα monochromatic
    heliograph at Mitaka.
Authors: Tanaka, N.; Yamaguchi, K.; Suematsu, Y.
Bibcode: 1993RNAOJ...1..361T
Altcode: 1993RNOAJ...1..361T
  A monochromatic heliograph has been in operation since 1957 at
  Mitaka. Recently the authors installed an automatic EE shutter control
  and a video monitor. Owing to this upgrade, the quality of solar images
  recorded on film has been improved significantly.

Title: Solar Flare Telescope project.
Authors: Ichimoto, K.; Sakurai, T.; Hiei, E.; Nishino, Y.; Shinoda, K.;
   Noguchi, M.; Imai, H.; Irie, M.; Miyashita, M.; Tanaka, N.; Kumagai,
   K.; Sano, I.; Suematsu, Y.; Okamoto, T.; Miyazaki, H.; Fukushima,
   H.; Yose, Y.; Zhao, Z. W.
Bibcode: 1993RNAOJ...1..375I
Altcode: 1993RNOAJ...1..375I
  The Solar Flare Telescope was built at Mitaka in 1989. This instrument
  comprises four telescopes which observe (1) Hα images, (2) continuum
  images, (3) vector magnetic fields, and (4) Doppler velocities,
  respectively. The instrument aims at the study of energy build-up
  and energy release in solar flares, in cooperation with the Solar-A
  satellite (Yohkoh). The Solar Flare Telescope has been in operation
  since 1990 December.

Title: Development of automatic detection system for solar Hα flares.
Authors: Tanaka, N.; Suematsu, Y.; Yamaguchi, K.
Bibcode: 1993RNAOJ...1..365T
Altcode: 1993RNOAJ...1..365T
  A new solar Hα flare patrol system was installed at National
  Astronomical Observatory, Mitaka and has been in operation since
  September, 1991. The new system consists of a φ 4 cm doublet, an Hα
  Lyot filter (pass band =0.5 Å), a 2/3 inch CCD camera, and a digital
  image analysis and storage unit. In the new system, Hα flares can
  be detected and be analyzed in real time by a computer. The authors
  describe the performance of the system and the methods of Hα flare
  detection and analysis.

Title: Magnetic Field Observation with the Solar Flare Telescope
Authors: Ichimoto, K.; Sakurai, T.; Nishino, Y.; Shinoda, K.; Noguchi,
   M.; Kumagai, K.; Imai, H.; Irie, M.; Miyashita, M.; Tanaka, N.; Sano,
   I.; Suematsu, Y.; Hiei, E.
Bibcode: 1993ASPC...46..166I
Altcode: 1993IAUCo.141..166I; 1993mvfs.conf..166I
  No abstract at ADS

Title: Kinematics and Lifetimes of Solar Spicules
Authors: Suematsu, Y.; Wang, H.; Zirin, H.
Bibcode: 1992AAS...180.0702S
Altcode: 1992BAAS...24..738S
  We present the dynamical evolution of spicules seen on the solar disk
  and the relationship between the spicule formation and Hα bright point
  at its footpoint. We used filtergrams in Hα -0.65 Angstroms, 0.0,
  and +0.65 Angstroms, (passband = 0.25 Angstroms) obtained at BBSO on
  Sep. 16, 1991, with the OSL CCD camera. The observations were made in
  a region of enhanced network for one and half hours. The resolution
  was 0.4 arcsec/pixel. The time resolution for the filtergrams of
  same wavelength was about 20 sec. These filtergrams were carefully
  registered with a cross-correlation technique, in order to follow the
  time evolution of fine structures. We investigated both proper motions
  and line-of-sight Doppler velocities of spicules; the latter were
  obtained from the subtraction of Hα -0.65 from +0.65 filtergrams. About
  2/3 of the spicules could be traced through up and down phases. For
  most short-lived spicules, both their apparent motions and Doppler
  velocities indicate that the motion of a spicule is real and it follows
  nearly a ballistic trajectory. For some long-lived spicules, we can
  see periodic rising motion. In these cases, we can see the lower part
  of the spicule showing downward motion even in the rising phase. The
  bright points, which are prominent in Hα blue wing, tend to appear or
  reach their maximum intensity at about the maximum phase of spicules,
  and to be accompanied with downward motions. It is likely that the
  Hα bright point does not initiate the spicule formation but rather
  it appears as a by-products of the spicule formation. These results
  seem to suggest that the spicules are generated by an impulsive upward
  force on the chromosphere such as a shock wave propagating upward,
  and its seed perturbation might take place at a layer deeper than the
  chromosphere, or might be a kinematic process with less heating if it
  occurs in the chromosphere.

Title: Numerical Simulations of Microflare Evolution in the Solar
    Transition Region and Corona
Authors: Sterling, Alphonse C.; Mariska, John T.; Shibata, Kazunari;
   Suematsu, Yoshinori
Bibcode: 1991ApJ...381..313S
Altcode:
  Several observers report transient ultraviolet brightenings, often
  referred to as microflares, in the solar atmosphere. In this paper,
  the results are presented of a series of one-dimensional numerical
  simulations examining possible relationships between microflares
  and the generation of dynamical chromospheric and transition region
  features. Low-energy and medium-energy microflares eject long-lived
  cool, dense gas plugs into the corona, with the gas plug traversing
  the loop apex in the medium energy case. In the case of high-energy
  microflares, the gas plug is rapidly heated to the temperature of the
  surrounding corona, and the results resemble the dynamics occurring
  in standard solar flare thick-target electron beam models.

Title: Chromospheric and Coronal Activities in the Quiet Sun
    Originating from Photospheric 5-Minute Oscillations
Authors: Suematsu, Yoshinori; Takeuchi, Akitsugu
Bibcode: 1991LNP...387..259S
Altcode: 1991fpsa.conf..259S
  We numerically investigated the non-linear response of the solar
  atmosphere to 5-min oscillations, assuming that atmospheric motions
  are restricted to flow along magnetic field lines. It was found that
  5-min oscillations can generate shock waves along magnetic field
  lines with inclination angles of about 50 degrees from vertical in
  the chromosphere. It is suggested that coronal activities driven by
  the shock waves might be observable with the Soft X-ray Telescope on
  board Solar-A.

Title: Solar Flare Telescope and 10-cm New Coronagraph
Authors: Ichimoto, K.; Sakurai, T.; Yamaguchi, A.; Kumagai, K.;
   Nishino, Y.; Suematsu, Y.; Hiei, E.; Hirayama, T.
Bibcode: 1991LNP...387..320I
Altcode: 1991fpsa.conf..320I
  Two new telescopes were built at the National Astronomical
  Observatory of Japan, i.e. the Solar Flare Telescope and the 10-cm New
  Coronagraph. The Solar Flare Telescope was constructed at Mitaka to make
  observations of photospheric velocity fields, vector magnetic fields,
  and H and continuum images of active regions simultaneously. The whole
  system will be completed in 1991. The 10-cm new coronagraph, which
  was developed to make precise measurements of the coronal intensity in
  several wavelengths, has already been in operation for one year at the
  Norikura Solar Observatory. At present the accuracy of about 10-6 of
  the solar disk intensity is achieved in continuum light, but further
  improvement in the photometric accuracy remains to be done.

Title: Oscillatory and Transient Features Detected Simultaneously
    in the CA II K and Hβ Line Spectra of a Quiescent Prominence
Authors: Suematsu, Yoshinori; Yoshinaga, Reiko; Terao, Naoko;
   Tsubaki, Tokio
Bibcode: 1990PASJ...42..187S
Altcode:
  Oscillatory time variations have been found in the line of sight Doppler
  velocity both in the Ca II K and Hβ lines at a faint edge-region of a
  quiescent prominence. The periods are about 240 and 830 s. Long-period
  variations of about 1 hr have also been detected at the same region in
  the Doppler velocity, integrated intensity, and line width. Moreover,
  a transient velocity variation of about 10 min time-span and 6 km
  s(-1) amplitude has been found at a region between the main bodies
  of the prominence. There is evidence that the temperature starts to
  increase before the Doppler velocity starts to increase in the case
  of the long-period variation, while the increases of temperature and
  Doppler velocity occur at the same time in the case of the transient
  feature. The possibility is suggested that some of the long-period
  oscillations might result from recurrent activation with heating in
  some part of the prominence, although short-period oscillations are
  not inconsistent with Alfven-wave-like ones.

Title: Influence of Photospheric 5-Minute Oscillations on the
    Formation of Chromospheric Fine Structures
Authors: Suematsu, Yoshinori
Bibcode: 1990LNP...367..211S
Altcode: 1990psss.conf..211S
  We present a basic idea how 5-minute oscillations can disturb the
  solar chromosphere significantly and show some results of numerical
  simulations in which the idea was examined.

Title: A coronal condensation observed at the total solar eclipse
    of June 11, 1983 and a related transient prominence
Authors: Suematsu, Yoshinori; Saito, Sumisaburo; Funakoshi, Yasuhiro;
   Kurokawa, Hiroki
Bibcode: 1988SoPh..116..285S
Altcode:
  A coronal condensation was observed simultaneously with Fexiv λ5303,
  Fex λ6374, Fe XI λ7892, and Hα filtergraphs. The size and shape
  of the condensation in λ5303 are different from those in other
  filtergrams. Hα filtergrams taken around the eclipse time show that a
  small transient prominence exists in close proximity to the condensation
  core and behaves like a post-flare loop system, though the appearance
  is quite different and no flare-report exists. A small-scale energetic
  phenomenon seems to have occurred at the top of magnetic loops.

Title: New evidence for oscillatory motions in a quiescent prominence
Authors: Tsubaki, Tokio; Toyoda, Minoru; Suematsu, Yoshinori; Gamboa,
   Guillermo A. R.
Bibcode: 1988PASJ...40..121T
Altcode:
  Detailed line-profile analyses have been carried out for Ca II K-line
  time-series spectra successively obtained at two graded heights in
  a quiescent prominence. Line-of-sight velocity variations of around
  10-min period, with amplitudes of 1.2 - 3.0 km s<SUP>-1</SUP>, have
  been detected successively over some 5,000 km at the corresponding
  locations of the both heights along the spectrograph slit, hereby
  providing new evidence for reconfirming the earlier result that there
  are some specific regions in prominences where periodic oscillations
  or waves can be amplified.

Title: Short-period oscillations found in a quiescent prominence
Authors: Tsubaki, Tokio; Ohnishi, Yumiko; Suematsu, Yoshinori
Bibcode: 1987PASJ...39..179T
Altcode:
  For the purpose of detecting periodic oscillations or waves in a
  quiescent prominence, time-series observations of Ca II K line spectra
  were carried out at the Hida Observatory. Detailed line-profile analyses
  followed by power spectral analyses have led to the conclusion that
  nearly the same phase of periodic oscillations, having a period of 160
  s and an amplitude of 0.8-1.4 km/s, were found in the line-of-sight
  Doppler velocity at successive locations over 15,000 km along the
  spectrograph slit. The intensity showed a slight indication for
  periodic fluctuations with a period of 240 s. In the line width,
  however, no periodicity was detected from the direct inspection of
  temporal variations from the power spectral analysis.

Title: Observational study for detecting periodic oscillations in
    the inner solar corona
Authors: Tsubaki, T.; Saito, Y.; Suematsu, Y.; Nakagomi, Y.
Bibcode: 1986PASJ...38..251T
Altcode:
  For the purpose of detecting periodic oscillations or waves in the inner
  corona, time series observations of Fe XIV λ5303 emission-line spectra
  were made at the Norikura Solar Observatory. Detailed line-profile
  analyses followed by power spectral analyses have provided the
  conclusion that periodic intensity fluctuations of nearly the same
  phase existed over some 100,000 km along the spectrograph slit with
  the same period of 235 s, and with the wavelength of 30,000 - 40,000
  km, while no periodicity was detected both for the line width and the
  line-of-sight Doppler velocity.

Title: Mass Motions due to Shock Propagations Along Low-Lying Loops
    in the Solar Atmosphere - on the Formation of Fibrils
Authors: Suematsu, Y.
Bibcode: 1985SoPh...98...67S
Altcode:
  The formation of fibrils in low-lying loops is investigated by
  performing one-dimensional nonlinear hydrodynamic calculations. The
  loops have the height of 3000-5000 km and have an atmosphere extending
  from the photosphere to the corona. A shock wave is generated from a
  pressure pulse in the photosphere and it ejects the chromosphere-corona
  transition region along the loop, expanding the underlying chromosphere
  into the corona. This expanding chromospheric material in a loop is
  regarded as a fibril. The shock propagates in the corona and collides
  with another transition region where a reflected shock and a penetrating
  shock are generated. The effect of the reflected shock on the motion
  of the fibril is weak. The fibril shows a nearly ballistic motion as
  observations suggest, if it does not extend beyond the summit of the
  loop. The corona in the loop is compressed nearly adiabatically by the
  fibril, and the enhanced coronal pressure leads the fibril finally to a
  retracting motion even if the fibril goes beyond the summit of the loop.

Title: Weakening of the Solar Extreme Ultraviolet Line Emission by
    Lyman Continuum Absorption as Derived from Line Ratios
Authors: Kanno, M.; Suematsu, Y.; Nishikawa, T.
Bibcode: 1984SoPh...91...71K
Altcode:
  The intensity ratios of NIII, OIII, OIV, and OV lines observed by
  the HCO experiment on Skylab are compared with the results of recent
  multilevel calculations. It is found that solar transition-region
  spectra require Lyman continuum absorption. The equivalent optical
  thickness of the absorbers causing the weakening is found to be 1.6-1.7
  for a quiet area, 1.4-1.9 for a coronal hole, and 2.4-2.5 for active
  regions. These values are consistent with previous estimates from
  different methods.

Title: Why are spicules absent over plages and long under coronal
    holes?
Authors: Shibata, K.; Suematsu, Y.
Bibcode: 1982SoPh...78..333S
Altcode:
  One-dimensional hydrodynamic simulations are performed in order
  to examine the influence of initial atmospheric structures on the
  dynamics of spicules. This is an extended version of our previous
  spicule theory: spicules are produced by the shock wave (MHD slow
  mode shock) which originates from a bright point appearance (sudden
  pressure increase) at the network in the photosphere or in the low
  chromosphere. Simulation results well reproduce the observational
  facts that spicules are absent over plages and long under coronal
  holes. The physical reason is that the growth of a shock wave during
  its propagation through the chromosphere is small in plage regions and
  large in coronal hole regions, since the growth of a shock is determined
  by the density ratio (ϱ<SUB>h</SUB><SUB>0</SUB>/ϱ<SUB>c</SUB>) between
  the bright point and the corona. An empirical formula ΔH<SUB>max</SUB>
  ∼ (ϱ<SUB>h</SUB><SUB>0</SUB>/ϱ<SUB>c</SUB>)<SUP>0.46</SUP> is
  obtained, where ΔH<SUB>max</SUB> is the maximum height of spicules
  above the transition region. The cross-section of the vertical magnetic
  flux tube is assumed to be constant in the numerical simulations.

Title: Numerical Hydrodynamics of the Jet Phenomena in the Solar
    Atmosphere - Part Two - Surges
Authors: Shibata, K.; Nishikawa, T.; Kitai, R.; Suematsu, Y.
Bibcode: 1982SoPh...77..121S
Altcode:
  One-dimensional hydrodynamic simulations of surges are performed in
  order to make clear their origin and structure. Surges are regarded as
  the jets resulting from a sudden pressure increase at the base of the
  model atmosphere. The height of the explosion (h<SUB>0</SUB>), which
  is measured from the level of τ<SUB>5000</SUB> = 1, is regarded as a
  free parameter. Another free parameter is the strength of the sudden
  pressure increase (p/p<SUB>0</SUB>) at h<SUB>0</SUB>. Simulations
  are performed for values in the ranges of 540 km ≤ h<SUB>0</SUB>
  ≤ 1920 km and 3 ≤ p/p<SUB>0</SUB> ≤ 30. It was found that for a
  fixed p/p<SUB>0</SUB> there exists a critical height (h<SUB>c</SUB>)
  in h<SUB>0</SUB>, which separates the jet (surge) models into two
  types. For h<SUB>0</SUB> &gt; h<SUB>c</SUB>, jets are produced directly
  by the pressure gradient force near h<SUB>0</SUB>, and made of the
  matter ejected from the explosion itself. The essential hydrodynamic
  structure of this type is the same as that in a shock tube (this type
  is called `shock tube' type). For h<SUB>0</SUB> &lt; h<SUB>c</SUB>,
  jets are not the direct results of the pressure enhancement, but
  are produced by the shock wave which are generated by the pressure
  enhancement and which has propagated through the chromosphere (this type
  is called the `crest shock' type). It is shown that the critical height
  (h<SUB>c</SUB>) ranges from 1000 km to 1500 km for 3 ≤ p/p<SUB>0</SUB>
  ≤ 30. General properties of both types are investigated in detail. The
  results are compared with observations and it is concluded that small
  surges associated with Ellerman bombsbelong to the `crest shock' type,
  i.e. they are produced by the shock wave.

Title: Wavelength Dependence of the Weakening of the Solar Extreme
    Ultraviolet Line Emission
Authors: Kanno, M.; Suematsu, Y.
Bibcode: 1982PASJ...34..449K
Altcode:
  The solar EUV emission from transition-region lines with wavelengths
  less than 912 Å is weakened by Lyman continuum absorption. Absorbers
  causing the weakening have not been detected in spatially resolved
  EUV and Hα observations. Two suggestions have been made on the
  origin of the weakening: the cloud model (Schmahl and Orrall 1979)
  and the overlapping model (Kanno 1979). <P />In this paper the
  empirical wavelength dependence of the weakening is studied for
  several types of regions of the solar atmosphere in order to know
  which of the models is consistent with observations. It is found that
  observations can be reasonably explained in terms of the cloud model
  where EUV emitting regions are overlain by clouds consisting of cool
  material. The optical thickness of the clouds at the Lyman continuum
  head ranges from 3 to 4 for the atmospheric regions discussed here;
  it implies that the geometrical thickness of the clouds is less than
  100 km, if the number density of neutral hydrogen in the clouds is
  some 10<SUP>11</SUP> cm<SUP>-3</SUP>. It is suggested that the clouds
  correspond to the remnants of cool chromospheric materials jetted into
  the corona such as Hα spicules.

Title: Numerical Hydrodynamics of the Jet Phenomena in the Solar
    Atmosphere - Part One - Spicules
Authors: Suematsu, Y.; Shibata, K.; Neshikawa, T.; Kitai, R.
Bibcode: 1982SoPh...75...99S
Altcode:
  We present a spicule model whose eruption occurs as a result of the
  sudden pressure enhancement at the bright point located at the root of
  the spicule. To show this, one dimensional (constant cross sectional)
  and time dependent hydrodynamic equations are solved numerically in
  the realistic solar atmosphere extending from the photosphere to
  the corona. Adiabatic motion is assumed. The pressure enhancement
  by a bright point at the base of the model atmosphere generates a
  shock wave. The shock gets stronger as it passes upward through the
  chromosphere and eventually collides with the chromosphere-corona
  interface which is a kind of a contact discontinuity. As the result,
  the interface begins to move upward. We identify the matter following
  behind this interface as the solar spicule. The model explains many
  observed features, such as the height and the density of the spicules,
  although such features have been hitherto considered not to be explained
  easily by shock theories.

Title: Numerical Hydrodynamic Simulations of Spicules
Authors: Suematsu, Y.
Bibcode: 1980jfss.conf...66S
Altcode:
  No abstract at ADS

