Author name code: jaeggli
ADS astronomy entries on 2022-09-14
author:"Jaeggli, Sarah A." 
------------------------------------------------------------------------  

Title: A Publicly Available Multiobservatory Data Set of an Enhanced
    Network Patch from the Photosphere to the Corona
Authors: Kobelski, Adam R.; Tarr, Lucas A.; Jaeggli, Sarah A.; Luber,
   Nicholas; Warren, Harry P.; Savage, Sabrina
Bibcode: 2022ApJS..261...15K
Altcode: 2022arXiv220501766K
  New instruments sensitive to chromospheric radiation at X-ray, UV,
  visible, IR, and submillimeter wavelengths have become available that
  significantly enhance our ability to understand the bidirectional
  flow of energy through the chromosphere. We describe the calibration,
  coalignment, initial results, and public release of a new data set
  combining a large number of these instruments to obtain multiwavelength
  photospheric, chromospheric, and coronal observations capable of
  improving our understanding of the connectivity between the photosphere
  and the corona via transient brightenings and wave signatures. The
  observations center on a bipolar region of enhanced-network
  magnetic flux near disk center on SOL2017-03-17T14:00-17:00. The
  comprehensive data set provides one of the most complete views to
  date of chromospheric activity related to small-scale brightenings
  in the corona and chromosphere. Our initial analysis shows a strong
  spatial correspondence between the areas of broadest width of the
  hydrogen-α spectral line and the hottest temperatures observed in
  Atacama Large Millimeter/submillimeter Array (ALMA) Band 3 radio
  data, with a linear coefficient of 6.12 × 10<SUP>-5</SUP>Å/K. The
  correspondence persists for the duration of cotemporal observations
  (≍60 m). Numerous transient brightenings were observed in multiple
  data series. We highlight a single, well-observed transient brightening
  in a set of thin filamentary features with a duration of 20 minutes. The
  timing of the peak intensity transitions from the cooler (ALMA, 7000 K)
  to the hotter (XRT, 3 MK) data series.

Title: Ground-based instrumentation and observational techniques
Authors: Rimmele, Thomas; Kuhn, Jeff; Woeger, Friedrich; Tritschler,
   . Alexandra; Lin, Haosheng; Casini, Roberto; Schad, Thomas; Jaeggli,
   Sarah; de Wijn, Alfred; Fehlmann, Andre; Anan, Tetsu; Schmidt, Dirk
Bibcode: 2022cosp...44.2507R
Altcode:
  We'll review the current state-of-the-art for ground-based
  instrumentation and techniques to achieve high-resolution
  observations. We'll use the 4m Daniel K. Inouye Solar Telescope
  (DKIST), the European Solar Telescope (EST) and other ground-based
  instrumentation as examples to demonstrate instrument designs
  and observing techniques. Using adaptive optics and post-facto
  image processing techniques, the recently completed DKIST provides
  unprecedented resolution and high polarimetric sensitivity that
  enables astronomers to unravel many of the mysteries the Sun presents,
  including the origin of solar magnetism, the mechanisms of coronal
  heating and drivers of flares and coronal mass ejections. Versatile
  ground-based instruments provide highly sensitive measurements of solar
  magnetic fields, that in the case of DKIST, also include measurements
  of the illusive magnetic field of the faint solar corona. Ground-based
  instruments produce large and diverse data sets that require complex
  calibration and data processing to provide science-ready to a broad
  community. We'll briefly touch on ongoing and future instrumentation
  developments, including multi-conjugate adaptive optics.

Title: Science Commissioning of the Diffraction-Limited Near-IR
    Spectropolarimter for the Daniel K. Inouye Solar Telescope
Authors: Lin, Haosheng; Schad, Thomas; Kramar, Maxim; Jaeggli, Sarah;
   Anan, Tetsu; Onaka, Peter
Bibcode: 2022cosp...44.2508L
Altcode:
  The Diffraction-Limited Near-IR Spectropolarimeter (DL-NIRSP) is one
  of the first-generation facility instruments of the Daniel K. Inouye
  Solar Telescope (DKIST, or The Inouye Solar Telescope). It is a near-IR
  spectropolarimeter optimized to study the magnetism of the dynamic solar
  atmosphere, from the photosphere to the corona. DL-NIRSP is equipped
  with two integral field units (IFUs) coupled to a high-resolution
  grating spectrograph, and is capable of simultaneous measurements
  of the full polarized spectra of a 2-dimensional spatial field
  without scanning. Large field of view observations are supported by
  mosaicking. DL-NIRSP observes simultaneously at three spectral windows,
  enabling simultaneous coverage of different atmospheric layers with
  carefully selected spectral lines. It can also observe the Sun with
  three resolution modes, from diffraction-limited observations with
  a spatial sampling of 0.03" to wide-field mode covering a 32"x15"
  instantaneous FOV with 0.5" sampling. This paper will present results
  from science commissioning observations conducted in late 2021.

Title: Thomson Scattering above Solar Active Regions and an Ad Hoc
    Polarization Correction Method for the Emissive Corona
Authors: Schad, Thomas A.; Jaeggli, Sarah A.; Dima, Gabriel I.
Bibcode: 2022ApJ...933...53S
Altcode: 2022arXiv220509808S
  Thomson-scattered photospheric light is the dominant constituent
  of the lower solar corona's spectral continuum viewed off-limb at
  optical wavelengths. Known as the K-corona, it is also linearly
  polarized. We investigate the possibility of using the a priori
  polarized characteristics of the K-corona, together with polarized
  emission lines, to measure and correct instrument-induced polarized
  crosstalk. First we derive the Stokes parameters of the Thomson
  scattering of unpolarized light in an irreducible spherical tensor
  formalism. This allows forward synthesis of the Thomson-scattered signal
  for the more complex scenario that includes symmetry-breaking features
  in the incident radiation field, which could limit the accuracy of our
  proposed technique. For this, we make use of an advanced 3D radiative
  magnetohydrodynamic coronal model. Together with synthesized polarized
  signals in the Fe XIII 10746 Å emission line, we find that an ad hoc
  correction of telescope- and instrument-induced polarization crosstalk
  is possible under the assumption of a nondepolarizing optical system.

Title: A Model-based Technique for Ad Hoc Correction of Instrumental
    Polarization in Solar Spectropolarimetry
Authors: Jaeggli, Sarah A.; Schad, Thomas A.; Tarr, Lucas A.;
   Harrington, David M.
Bibcode: 2022ApJ...930..132J
Altcode: 2022arXiv220403732J
  We present a new approach for correcting instrumental polarization by
  modeling the nondepolarizing effects of a complex series of optical
  elements to determine physically realizable Mueller matrices. Provided
  that the Mueller matrix of the optical system can be decomposed into
  a general elliptical diattenuator and general elliptical retarder,
  it is possible to model the crosstalk between both the polarized and
  unpolarized states of the Stokes vector and then use the acquired
  science observations to determine the best-fit free parameters. Here
  we implement a minimization for solar spectropolarimetric measurements
  containing photospheric spectral lines sensitive to the Zeeman effect
  using physical constraints provided by polarized line and continuum
  formation. This model-based approach is able to provide an accurate
  correction even in the presence of large amounts of polarization
  crosstalk and conserves the physically meaningful magnitude of
  the Stokes vector, a significant improvement over previous ad hoc
  techniques.

Title: Probing the Physics of the Solar Atmosphere with the Multi-slit
    Solar Explorer (MUSE). II. Flares and Eruptions
Authors: Cheung, Mark C. M.; Martínez-Sykora, Juan; Testa, Paola;
   De Pontieu, Bart; Chintzoglou, Georgios; Rempel, Matthias; Polito,
   Vanessa; Kerr, Graham S.; Reeves, Katharine K.; Fletcher, Lyndsay; Jin,
   Meng; Nóbrega-Siverio, Daniel; Danilovic, Sanja; Antolin, Patrick;
   Allred, Joel; Hansteen, Viggo; Ugarte-Urra, Ignacio; DeLuca, Edward;
   Longcope, Dana; Takasao, Shinsuke; DeRosa, Marc L.; Boerner, Paul;
   Jaeggli, Sarah; Nitta, Nariaki V.; Daw, Adrian; Carlsson, Mats; Golub,
   Leon; The
Bibcode: 2022ApJ...926...53C
Altcode: 2021arXiv210615591C
  Current state-of-the-art spectrographs cannot resolve the fundamental
  spatial (subarcseconds) and temporal (less than a few tens of
  seconds) scales of the coronal dynamics of solar flares and eruptive
  phenomena. The highest-resolution coronal data to date are based on
  imaging, which is blind to many of the processes that drive coronal
  energetics and dynamics. As shown by the Interface Region Imaging
  Spectrograph for the low solar atmosphere, we need high-resolution
  spectroscopic measurements with simultaneous imaging to understand the
  dominant processes. In this paper: (1) we introduce the Multi-slit Solar
  Explorer (MUSE), a spaceborne observatory to fill this observational
  gap by providing high-cadence (&lt;20 s), subarcsecond-resolution
  spectroscopic rasters over an active region size of the solar transition
  region and corona; (2) using advanced numerical models, we demonstrate
  the unique diagnostic capabilities of MUSE for exploring solar coronal
  dynamics and for constraining and discriminating models of solar flares
  and eruptions; (3) we discuss the key contributions MUSE would make
  in addressing the science objectives of the Next Generation Solar
  Physics Mission (NGSPM), and how MUSE, the high-throughput Extreme
  Ultraviolet Solar Telescope, and the Daniel K Inouye Solar Telescope
  (and other ground-based observatories) can operate as a distributed
  implementation of the NGSPM. This is a companion paper to De Pontieu
  et al., which focuses on investigating coronal heating with MUSE.

Title: Probing the Physics of the Solar Atmosphere with the Multi-slit
Solar Explorer (MUSE): II. Flares and Eruptions
Authors: Cheung, Chun Ming Mark; Martinez-Sykora, Juan; Testa, Paola;
   De Pontieu, Bart; Chintzoglou, Georgios; Rempel, Matthias; Polito,
   Vanessa; Kerr, Graham; Reeves, Katharine; Fletcher, Lyndsay; Jin,
   Meng; Nobrega, Daniel; Danilovic, Sanja; Antolin, Patrick; Allred,
   Joel; Hansteen, Viggo; Ugarte-Urra, Ignacio; DeLuca, Edward; Longcope,
   Dana; Takasao, Shinsuke; DeRosa, Marc; Boerner, Paul; Jaeggli, Sarah;
   Nitta, Nariaki; Daw, Adrian; Carlsson, Mats; Golub, Leon
Bibcode: 2021AGUFMSH51A..08C
Altcode:
  Current state-of-the-art spectrographs cannot resolve the fundamental
  spatial (sub-arcseconds) and temporal scales (less than a few tens
  of seconds) of the coronal dynamics of solar flares and eruptive
  phenomena. The highest resolution coronal data to date are based on
  imaging, which is blind to many of the processes that drive coronal
  energetics and dynamics. As shown by IRIS for the low solar atmosphere,
  we need high-resolution spectroscopic measurements with simultaneous
  imaging to understand the dominant processes. In this paper: (1)
  we introduce the Multi-slit Solar Explorer (MUSE), a spaceborne
  observatory to fill this observational gap by providing high-cadence
  (&lt;20 s), sub-arcsecond resolution spectroscopic rasters over an
  active region size of the solar transition region and corona; (2)
  using advanced numerical models, we demonstrate the unique diagnostic
  capabilities of MUSE for exploring solar coronal dynamics, and for
  constraining and discriminating models of solar flares and eruptions;
  (3) we discuss the key contributions MUSE would make in addressing the
  science objectives of the Next Generation Solar Physics Mission (NGSPM),
  and how MUSE, the high-throughput EUV Solar Telescope (EUVST) and the
  Daniel K Inouye Solar Telescope (and other ground-based observatories)
  can operate as a distributed implementation of the NGSPM. This is a
  companion paper to De Pontieu et al. (2021, also submitted to SH-17),
  which focuses on investigating coronal heating with MUSE.

Title: Chromospheric Heating Mechanisms in a Plage Region Constrained
    by Comparison of Magnetic Field and Mg II h &amp; k Flux Measurements
    with Theoretical Studies
Authors: Anan, Tetsu; Schad, Thomas; Kitai, Reizaburo; Dima, Gabriel;
   Jaeggli, Sarah; Tarr, Lucas; Collados, Manuel; Dominguez-Tagle,
   Carlos; Kleint, Lucia
Bibcode: 2021AGUFMSH44A..05A
Altcode:
  The strongest quasi-steady heating in the solar atmosphere from the
  photosphere through the corona occurs in plage regions. As many
  chromospheric heating mechanisms have been proposed, important
  discriminators of the possible mechanisms are the location of the
  heating and the correlation between the magnetic field properties in
  the chromosphere and the local heating rate. We observed a plage region
  with the He I 1083.0 nm and Si I 1082.7 nm lines on 2018 October 3
  using the integral field unit mode of the GREGOR Infrared Spectrograph
  (GRIS) installed at the GREGOR telescope. During the GRIS observation,
  the Interface Region Imaging Spectrograph (IRIS) obtained spectra of the
  ultraviolet Mg II h &amp; k doublet emitted from the same region. In
  the periphery of the plage region, within the limited field of view
  seen by GRIS, we find that the Mg II radiative flux increases with the
  magnetic field in the chromosphere. The positive correlation implies
  that magnetic flux tubes can be heated by Alfvén wave turbulence
  or by collisions between ions and neutral atoms relating to Alfvén
  waves. Within the plage region itself, the radiative flux was large
  between patches of strong magnetic field strength in the photosphere, or
  at the edges of magnetic patches. On the other hand, we do not find any
  significant spatial correlation between the enhanced radiative flux and
  the chromospheric magnetic field strength or the electric current. In
  addition to the Alfvén wave turbulence or collisions between ions
  and neutral atoms relating to Alfvén waves, other heating mechanisms
  related to magnetic field perturbations produced by interactions of
  magnetic flux tubes could be at work in the plage chromosphere.

Title: Measurements of Photospheric and Chromospheric Magnetic
    Field Structures Associated with Chromospheric Heating over a Solar
    Plage Region
Authors: Anan, Tetsu; Schad, Thomas A.; Kitai, Reizaburo; Dima,
   Gabriel I.; Jaeggli, Sarah A.; Tarr, Lucas A.; Collados, Manuel;
   Dominguez-Tagle, Carlos; Kleint, Lucia
Bibcode: 2021ApJ...921...39A
Altcode: 2021arXiv210807907A
  In order to investigate the relation between magnetic structures and
  the signatures of heating in plage regions, we observed a plage region
  with the He I 1083.0 nm and Si I 1082.7 nm lines on 2018 October 3
  using the integral field unit mode of the GREGOR Infrared Spectrograph
  (GRIS) installed at the GREGOR telescope. During the GRIS observation,
  the Interface Region Imaging Spectrograph obtained spectra of the
  ultraviolet Mg II doublet emitted from the same region. In the periphery
  of the plage region, within the limited field of view seen by GRIS,
  we find that the Mg II radiative flux increases with the magnetic
  field in the chromosphere with a factor of proportionality of 2.38 ×
  10<SUP>4</SUP> erg cm<SUP>-2</SUP> s<SUP>-1</SUP> G<SUP>-1</SUP>. The
  positive correlation implies that magnetic flux tubes can be heated
  by Alfvén wave turbulence or by collisions between ions and neutral
  atoms relating to Alfvén waves. Within the plage region itself,
  the radiative flux was large between patches of strong magnetic field
  strength in the photosphere or at the edges of magnetic patches. On
  the other hand, we do not find any significant spatial correlation
  between the enhanced radiative flux and the chromospheric magnetic
  field strength or the electric current. In addition to the Alfvén
  wave turbulence or collisions between ions and neutral atoms relating
  to Alfvén waves, other heating mechanisms related to magnetic field
  perturbations produced by interactions of magnetic flux tubes could
  be at work in the plage chromosphere.

Title: The National Science Foundation's Daniel K. Inouye Solar
    Telescope — Status Update
Authors: Rimmele, T.; Woeger, F.; Tritschler, A.; Casini, R.; de Wijn,
   A.; Fehlmann, A.; Harrington, D.; Jaeggli, S.; Anan, T.; Beck, C.;
   Cauzzi, G.; Schad, T.; Criscuoli, S.; Davey, A.; Lin, H.; Kuhn, J.;
   Rast, M.; Goode, P.; Knoelker, M.; Rosner, R.; von der Luehe, O.;
   Mathioudakis, M.; Dkist Team
Bibcode: 2021AAS...23810601R
Altcode:
  The National Science Foundation's 4m Daniel K. Inouye Solar Telescope
  (DKIST) on Haleakala, Maui is now the largest solar telescope in the
  world. DKIST's superb resolution and polarimetric sensitivity will
  enable astronomers to unravel many of the mysteries the Sun presents,
  including the origin of solar magnetism, the mechanisms of coronal
  heating and drivers of flares and coronal mass ejections. Five
  instruments, four of which provide highly sensitive measurements
  of solar magnetic fields, including the illusive magnetic field of
  the faint solar corona. The DKIST instruments will produce large and
  complex data sets, which will be distributed through the NSO/DKIST Data
  Center. DKIST has achieved first engineering solar light in December
  of 2019. Due to COVID the start of the operations commissioning phase
  is delayed and is now expected for fall of 2021. We present a status
  update for the construction effort and progress with the operations
  commissioning phase.

Title: Magnetic field structures associated with chromospheric
    heating in a plage region
Authors: Anan, T.; Schad, T.; Kitai, R.; Dima, G.; Jaeggli, S.;
   Collados, M.; Dominguez-Tagle, C.; Kleint, L.
Bibcode: 2021AAS...23821222A
Altcode:
  The strongest quasi-steady heating in the solar atmosphere occurs in
  the active chromosphere and in particular within plage regions. Our
  aim is to investigate the relation between magnetic structures and
  the signatures of heating in the plage regions so as to clarify what
  mechanisms are at work. We observed a plage region in NOAA active
  region 12723 in the near infrared He I triplet and Si I 1082.7 nm
  on 2018 October 3 using the Integral Field Unit mode of the GREGOR
  Infrared Spectrograph (GRIS) installed at the GREGOR telescope. At the
  same time, the Interface Region Imaging Spectrograph (IRIS) obtained
  spectra in the ultra-violet Mg II h &amp; k doublet emitted from the
  same region. We applied the HAnle and ZEeman Light v2.0 inversion
  code (HAZEL v2.0) to the GRIS data to infer the photospheric and
  chromospheric magnetic field. We find that the radiative flux of the Mg
  II was large between patches of strong magnetic field strength in the
  photosphere, or at edges of the magnetic patches. On the other hand,
  the spatial correspondences between the Mg II flux and the magnetic
  field strength in the chromosphere and between the Mg II flux and the
  electric current are not so clear. In conclusion, chromospheric heatings
  in the plage region can be related to magnetic field perturbations
  produced by interactions of magnetic flux tubes.

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: Using Molecules to Investigate Cool Gas on the Sun with DKIST
Authors: Jaeggli, Sarah
Bibcode: 2021cosp...43E.970J
Altcode:
  Simple molecules form in the solar atmosphere in regions of cool
  plasma. Molecules are physically interesting and provide critical
  diagnostics of cool plasma. They are sensitive to temperature
  and pressure, and some molecular lines are even magnetically
  sensitive. Strong absorption lines from molecules such as OH,
  CN, and CO are prominent in sunspot spectra. Molecular hydrogen,
  which has a noted absence of lines in the visible and infrared, may
  actually be the most abundant molecular species, comprising 10% of the
  total hydrogen population in very cool sunspot umbrae. CH, which is
  ubiquitous in the quiet-Sun, dissociates in hotter regions, revealing
  the features known as G-band bright points. The strongest lines of
  the fundamental band of CO at 4.6 um reveal what has been interpreted
  as a mix of hot and cool gas at the roots of the chromosphere. The
  U.S. National Science Foundation's Daniel K. Inouye Solar Telescope
  (DKIST) will provide new observations of the Sun with unprecedented
  spatial and temporal resolution. DKIST instruments are designed
  to target atomic and molecular diagnostics to address a variety of
  science cases. Molecular diagnostics throughout the visible spectrum
  can be explored with the Visible Spectropolarimeter (ViSP). The
  Diffraction-Limited Near-Infrared Spectropolarimeter (DL-NIRSP) can
  be used to explore the dynamic behavior of OH in sunspots alongside
  sensitive magnetic field diagnostics of Fe I at 1565 nm using its
  integral field unit. The Cryogenic Near-Infrared Spectropolarimeter
  will provide the chance for detailed study of the 4.6 um CO lines on
  disk and at the limb.

Title: The Daniel K. Inouye Solar Telescope - Observatory Overview
Authors: Rimmele, Thomas R.; Warner, Mark; Keil, Stephen L.; Goode,
   Philip R.; Knölker, Michael; Kuhn, Jeffrey R.; Rosner, Robert R.;
   McMullin, Joseph P.; Casini, Roberto; Lin, Haosheng; Wöger, Friedrich;
   von der Lühe, Oskar; Tritschler, Alexandra; Davey, Alisdair; de Wijn,
   Alfred; Elmore, David F.; Fehlmann, André; Harrington, David M.;
   Jaeggli, Sarah A.; Rast, Mark P.; Schad, Thomas A.; Schmidt, Wolfgang;
   Mathioudakis, Mihalis; Mickey, Donald L.; Anan, Tetsu; Beck, Christian;
   Marshall, Heather K.; Jeffers, Paul F.; Oschmann, Jacobus M.; Beard,
   Andrew; Berst, David C.; Cowan, Bruce A.; Craig, Simon C.; Cross,
   Eric; Cummings, Bryan K.; Donnelly, Colleen; de Vanssay, Jean-Benoit;
   Eigenbrot, Arthur D.; Ferayorni, Andrew; Foster, Christopher; Galapon,
   Chriselle Ann; Gedrites, Christopher; Gonzales, Kerry; Goodrich, Bret
   D.; Gregory, Brian S.; Guzman, Stephanie S.; Guzzo, Stephen; Hegwer,
   Steve; Hubbard, Robert P.; Hubbard, John R.; Johansson, Erik M.;
   Johnson, Luke C.; Liang, Chen; Liang, Mary; McQuillen, Isaac; Mayer,
   Christopher; Newman, Karl; Onodera, Brialyn; Phelps, LeEllen; Puentes,
   Myles M.; Richards, Christopher; Rimmele, Lukas M.; Sekulic, Predrag;
   Shimko, Stephan R.; Simison, Brett E.; Smith, Brett; Starman, Erik;
   Sueoka, Stacey R.; Summers, Richard T.; Szabo, Aimee; Szabo, Louis;
   Wampler, Stephen B.; Williams, Timothy R.; White, Charles
Bibcode: 2020SoPh..295..172R
Altcode:
  We present an overview of the National Science Foundation's Daniel
  K. Inouye Solar Telescope (DKIST), its instruments, and support
  facilities. The 4 m aperture DKIST provides the highest-resolution
  observations of the Sun ever achieved. The large aperture of
  DKIST combined with state-of-the-art instrumentation provide the
  sensitivity to measure the vector magnetic field in the chromosphere
  and in the faint corona, i.e. for the first time with DKIST we will
  be able to measure and study the most important free-energy source
  in the outer solar atmosphere - the coronal magnetic field. Over its
  operational lifetime DKIST will advance our knowledge of fundamental
  astronomical processes, including highly dynamic solar eruptions
  that are at the source of space-weather events that impact our
  technological society. Design and construction of DKIST took over two
  decades. DKIST implements a fast (f/2), off-axis Gregorian optical
  design. The maximum available field-of-view is 5 arcmin. A complex
  thermal-control system was implemented in order to remove at prime
  focus the majority of the 13 kW collected by the primary mirror and
  to keep optical surfaces and structures at ambient temperature, thus
  avoiding self-induced local seeing. A high-order adaptive-optics
  system with 1600 actuators corrects atmospheric seeing enabling
  diffraction limited imaging and spectroscopy. Five instruments, four
  of which are polarimeters, provide powerful diagnostic capability
  over a broad wavelength range covering the visible, near-infrared,
  and mid-infrared spectrum. New polarization-calibration strategies
  were developed to achieve the stringent polarization accuracy
  requirement of 5×10<SUP>−4</SUP>. Instruments can be combined and
  operated simultaneously in order to obtain a maximum of observational
  information. Observing time on DKIST is allocated through an open,
  merit-based proposal process. DKIST will be operated primarily in
  "service mode" and is expected to on average produce 3 PB of raw
  data per year. A newly developed data center located at the NSO
  Headquarters in Boulder will initially serve fully calibrated data to
  the international users community. Higher-level data products, such as
  physical parameters obtained from inversions of spectro-polarimetric
  data will be added as resources allow.

Title: Polarization modeling and predictions for Daniel K. Inouye
Solar Telescope, part 6: fringe mitigation with polycarbonate
    modulators and optical contact calibration retarders
Authors: Harrington, David M.; Jaeggli, Sarah A.; Schad, Tom A.;
   White, Amanda J.; Sueoka, Stacey R.
Bibcode: 2020JATIS...6c8001H
Altcode:
  Interference fringes are a major source of systematic error in
  astronomical spectropolarimeters. We apply the Berreman formalism
  with recent spatial fringe aperture averaging estimates to design and
  fabricate new fringe-suppressed polarization optics for several Daniel
  K. Inouye Solar Telescope (DKIST) use cases. We successfully performed
  an optical contact bond on a 120-mm-diameter compound crystal retarder
  for calibration with wavelength-dependent fringe suppression factors
  of one to three orders of magnitude. Special rotational alignment
  procedures were developed to minimize spectral oscillations, which
  we show here to represent our calibration stability limit under
  retarder thermal perturbation. We developed a fabrication technique
  to deliver low beam deflection for our large aperture polycarbonate
  (PC) retarders. Modulators are upgraded in two DKIST instruments
  with minimal beam deflection and bandpass-optimized antireflection
  coatings for fringe suppression factors of hundreds. We confirm that
  PC retarders do fringe as expected when low deflection is achieved. We
  show that increased retardance spatial variation from PC does not
  degrade modulation efficiency.

Title: Observing Solar Plasma Environments with DKIST
Authors: Jaeggli, Sarah
Bibcode: 2020APS..DPPD02001J
Altcode:
  The Sun displays diverse plasma environments structured by magnetic
  fields. The largely neutral photosphere is sprinkled with ∼1 kG
  magnetic fields rooted in the underlying convection zone. Just above
  this magneto-acoustic shocks and rapidly expanding magnetic fields
  create complex and dynamic structures interspersed with quiescent
  and eruptive phenomena in the chromosphere. The average temperature
  increases through the chromosphere abruptly jumps to &gt;10<SUP>6</SUP>
  K in the solar corona. These different regimes are directly coupled by
  many processes that have been extensively studied using a combination
  of theory, simulations, and laboratory experiments: dynamos, waves,
  instabilities, and reconnection. The National Science Foundation's
  Daniel K. Inouye Solar Telescope is an unprecedented new facility that
  will allow for measurements of the highest spatial resolution and superb
  signal to noise on shorter timescales than ever before. First light
  instruments will provide simultaneous multi-wavelength observations
  with spectral and polarimetric capabilities on disk and above the
  limb. Coupled with radiative MHD modeling, this can provide 3D diagnosis
  of plasma parameters (e.g. magnetic field vector, temperature) over
  the plasma regimes found throughout the Sun's atmosphere.

Title: Shock Heating Energy of Umbral Flashes Measured with Integral
    Field Unit Spectroscopy
Authors: Anan, Tetsu; Schad, Thomas A.; Jaeggli, Sarah A.; Tarr,
   Lucas A.
Bibcode: 2019ApJ...882..161A
Altcode: 2019arXiv190710797A
  Umbral flashes are periodic brightness increases routinely observed in
  the core of chromospheric lines within sunspot umbrae and are attributed
  to propagating shock fronts. In this work we quantify the shock heating
  energy of these umbral flashes using observations in the near-infrared
  He I triplet obtained on 2014 December 7 with the SpectroPolarimetric
  Imager for the Energetic Sun, which is a novel integral field unit
  spectrograph at the Dunn Solar Telescope. We determine the shock
  properties (the Mach number and the propagation speed) by fitting
  the measured He I spectral profiles with a theoretical radiative
  transfer model consisting of two constant-property atmospheric slabs
  whose temperatures and macroscopic velocities are constrained by the
  Rankine-Hugoniot relations. From the Mach number, the shock heating
  energy per unit mass of plasma is derived to be 2 × 10<SUP>10</SUP>
  erg g<SUP>-1</SUP>, which is insufficient to maintain the umbral
  chromosphere. In addition, we find that the shocks propagate upward with
  the sound speed and the Mach number does not depend on the temperature
  upstream of the shocks. The latter may imply suppression of the
  amplification of the Mach number due to energy loss of the shocks.

Title: Optical Alignment of DL-NIRSP Spectrograph
Authors: Jaeggli, Sarah A.; Anan, Tetsu; Kramar, Maxim; Lin, Haosheng
Bibcode: 2019AAS...23410612J
Altcode:
  The Diffraction-Limited Near-Infrared Spectropolarimeter (DL-NIRSP)
  will be delivered as part of the first light instrumentation for the
  Daniel K. Inouye Solar Telescope (DKIST) and is currently undergoing
  lab integration at the University of Hawai'i Institute for Astronomy's
  Advanced Technology Research Center on Maui. An off-axis hyperbolic
  mirror, with a focal length of 1250 mm, is used as both collimator
  and camera in the spectrograph, and makes this system particularly
  difficult to align. The optical axis, or vertex, of the parent surface
  is located approximately 260 mm from the center of the off-axis
  section of the mirror, but there is no direct physical or optical
  reference for the location and orientation of the optical axis. We
  have made use of vendor data and a coordinate measuring machine (CMM)
  arm to transfer coordinates from the back and perimeter surfaces of
  the mirror to locate the optical axis focus and place the other optical
  components in reference to this mechanical model. In coordination, we
  have conducted tests of the optical quality at various points during
  the alignment to ensure that the mechanical tolerances maintain the
  optical quality of the system so that the instrument will be able to
  achieve excellent spectral resolution limited by the spectrograph slit
  width (λ/Δλ 250,000), and preserve the diffraction limited spatial
  resolution provided by the telescope and feed optics (0.06" at 1 μm).

Title: Transient dynamics and energy transfer from the photosphere
to the low corona: initial results from a coordinated ALMA, DST,
    Hinode, IRIS, and SDO observation campaign
Authors: Kobelski, Adam; Tarr, Lucas A.; Jaeggli, Sarah A.; Savage,
   Sabrina
Bibcode: 2019AAS...23430702K
Altcode:
  We present initial results from a coordinated observation campaign
  to study transient dynamics and energy transfer in the low solar
  atmosphere. The observations ran from approximately 2017-03-21 from
  13UT to 19UT, and include data from Hinode, IRIS, DST, and ALMA. The
  target, a small, magnetically bipolar active area associated with a
  coronal bright point, was chosen for showing reasonable dynamics in the
  chromosphere (as dictated by AIA 304 data from the day prior), and being
  near disk center to better facilitate magnetic field measurement. The
  campaign was designed to capture the dynamics of the target with as
  rapid a timescale as possible for each instrument. Photospheric dynamics
  are available from broadband IBIS data and the HMI. New to this dataset,
  the chromospheric dynamics were observed in radio frequencies using ALMA
  (Band 3: 92-108GHz) at a 2s cadence. Additional chromospheric data are
  spectral H-α from the IBIS instrument at the DST, spectropolarimetic
  HeI 10830 from the FIRS instrument at the DST, and the medium linelist
  from IRIS; coronal data includes imaging from XRT and spectral data
  from EIS. In this first set of results, we discuss the frequency of
  transient brightenings observed in each set of imaging data and how
  the spatial distribution relates across each data channel and to the
  regions magnetic topology.

Title: Shock heating energy in an umbra of a sunspot with integral
    field unit spectroscopy
Authors: Anan, Tetsu; Schad, Thomas A.; Jaeggli, Sarah A.; Tarr,
   Lucas A.
Bibcode: 2019AAS...23421705A
Altcode:
  On 2014 December 7 we used new integral field spectroscopy techniques
  to observe umbral flashes, which are periodic brightness increases
  routinely observed in the core of chromospheric lines within sunspot
  umbrae and are attributed to propagating shock fronts. In this work
  we quantify the shock heating energy of these umbral flashes using
  observations in the near infrared HeI triplet obtained with the
  SpectroPolarimetric Imager for the Energetic Sun (SPIES), which is
  novel integral field unit spectrograph at the Dunn Solar Telescope. We
  determine the shock properties (the Mach number and the propagation
  speed) by fitting the measured HeI spectral profiles with a theoretical
  radiative transfer model using two constant property atmospheric slabs
  whose temperatures and macroscopic velocities are constrained by the
  Rankine-Hugoniot relations. From the Mach number, the shock heating
  energy per unit mass of plasma is derived as 2 x 10<SUP>10</SUP>
  erg/g. We conclude that the estimated shock heating energy rate is
  less than the amount required to maintain the umbral chromosphere.

Title: Shock Heating Energy in an umbra of a sunspot
Authors: Anan, Tetsu; Schad, Tom; Jaeggli, Sarah
Bibcode: 2019EGUGA..2113543A
Altcode:
  In December 7, 2014, umbral flashes, which are periodic brightness
  increases in chromospheric spectral lines of the umbrae due to shocks,
  were observed in near infrared He I triplet with an integral-field-unit
  spectrometer, SPIES (SpectroPolarimetric Imager for the Energetic Sun)
  on the Dunn Solar Telescope with a cadence of 14 seconds. The SPIES is
  a prototype instruments of a facility instrument of the Daniel K. Inouye
  Solar Telescope. In order to determine Mach number at upstream of shock
  waves, we fit the measured spectral profiles in the He I 1083 nm triplet
  with theoretical profiles computed with a radiative transfer equation
  using an atmospheric model based on two constant property slabs, of
  which temperatures and macroscopic velocities are constrained by the
  Rankine-Hugoniot relations. From the Mach number and the temperature,
  shock heating energy per unit mass of plasma is derived as 2.0 x 10 ^
  {10} erg/g. Finding a positive correlation between a spatial variation
  of the chromospheric temperature and shock speed, we concluded that
  prominent heating mechanism can be related with the shock, although
  estimated shock heating energy rate is less than the required amount
  of energy to maintain the umbral chromosphere.

Title: VizieR Online Data Catalog: UV spectrum of molecular hydrogen
    in the Sun (Jaeggli+, 2018)
Authors: Jaeggli, S. A.; Judge, P. G.; Daw, A. N.
Bibcode: 2019yCat..18550134J
Altcode:
  Ultraviolet (UV) lines of molecular hydrogen have been observed in
  solar spectra for almost four decades, but the behavior of the molecular
  spectrum and its implications for solar atmospheric structure are not
  fully understood. Data from the High-Resolution Telescope Spectrometer
  (HRTS) instrument revealed that H2 emission forms in particular regions,
  selectively excited by a bright UV transition region and chromospheric
  lines. We test the conditions under which H2 emission can originate
  by studying non-LTE models, sampling a broad range of temperature
  stratifications and radiation conditions. Stratification plays the
  dominant role in determining the population densities of H2, which
  forms in greatest abundance near the continuum photosphere. However,
  opacity due to the photoionization of Si and other neutrals determines
  the depth to which UV radiation can penetrate to excite the H2. Thus
  the majority of H2 emission forms in a narrow region, at about 650km
  in standard one-dimensional (1D) models of the quiet Sun, near the
  {tau}=1 opacity surface for the exciting UV radiation, generally coming
  from above. When irradiated from above using observed intensities of
  bright UV emission lines, detailed non-LTE calculations show that the
  spectrum of H2 seen in the quiet-Sun Solar Ultraviolet Measurement of
  Emitted Radiation atlas spectrum and HRTS light-bridge spectrum can
  be satisfactorily reproduced in 1D stratified atmospheres, without
  including three-dimensional or time-dependent thermal structures. A
  detailed comparison to observations from 1205 to 1550Å is presented,
  and the success of this 1D approach to modeling solar UV H2 emission
  is illustrated by the identification of previously unidentified lines
  and upper levels in HRTS spectra. <P />(3 data files).

Title: Instrument Calibration of the Interface Region Imaging
    Spectrograph (IRIS) Mission
Authors: Wülser, J. -P.; Jaeggli, S.; De Pontieu, B.; Tarbell,
   T.; Boerner, P.; Freeland, S.; Liu, W.; Timmons, R.; Brannon, S.;
   Kankelborg, C.; Madsen, C.; McKillop, S.; Prchlik, J.; Saar, S.;
   Schanche, N.; Testa, P.; Bryans, P.; Wiesmann, M.
Bibcode: 2018SoPh..293..149W
Altcode:
  The Interface Region Imaging Spectrograph (IRIS) is a NASA small
  explorer mission that provides high-resolution spectra and images of
  the Sun in the 133 - 141 nm and 278 - 283 nm wavelength bands. The
  IRIS data are archived in calibrated form and made available to the
  public within seven days of observing. The calibrations applied to
  the data include dark correction, scattered light and background
  correction, flat fielding, geometric distortion correction, and
  wavelength calibration. In addition, the IRIS team has calibrated the
  IRIS absolute throughput as a function of wavelength and has been
  tracking throughput changes over the course of the mission. As a
  resource for the IRIS data user, this article describes the details
  of these calibrations as they have evolved over the first few years
  of the mission. References to online documentation provide access to
  additional information and future updates.

Title: Predictions of DKIST/DL-NIRSP Observations for an Off-limb
    Kink-unstable Coronal Loop
Authors: Snow, B.; Botha, G. J. J.; Scullion, E.; McLaughlin, J. A.;
   Young, P. R.; Jaeggli, S. A.
Bibcode: 2018ApJ...863..172S
Altcode: 2018arXiv180704972S
  Synthetic intensity maps are generated from a 3D kink-unstable flux
  rope simulation using several DKIST/DL-NIRSP spectral lines to make
  a prediction of the observational signatures of energy transport and
  release. The reconstructed large field-of-view intensity mosaics and
  single tile sit-and-stare high-cadence image sequences show detailed,
  fine-scale structure and exhibit signatures of wave propagation,
  redistribution of heat, flows, and fine-scale bursts. These fine-scale
  bursts are present in the synthetic Doppler velocity maps and can be
  interpreted as evidence for small-scale magnetic reconnection at the
  loop boundary. The spectral lines reveal the different thermodynamic
  structures of the loop, with the hotter lines showing the loop
  interior and braiding and the cooler lines showing the radial edges
  of the loop. The synthetic observations of DL-NIRSP are found to
  preserve the radial expansion, and hence the loop radius can be
  measured accurately. The electron number density can be estimated
  using the intensity ratio of the Fe XIII lines at 10747 and 10798
  Å. The estimated density from this ratio is correct to within ±10%
  during the later phases of the evolution; however, it is less accurate
  initially when line-of-sight density inhomogeneities contribute to the
  Fe XIII intensity, resulting in an overprediction of the density by
  ≈30%. The identified signatures are all above a conservative estimate
  for instrument noise and therefore will be detectable. In summary, we
  have used forward modeling to demonstrate that the coronal off-limb
  mode of DKIST/DL-NIRSP will be able to detect multiple independent
  signatures of a kink-unstable loop and observe small-scale transient
  features including loop braiding/twisting and small-scale reconnection
  events occurring at the radial edge of the loop.

Title: Status of the Daniel K. Inouye Solar Telescope: unraveling
    the mysteries the Sun.
Authors: Rimmele, Thomas R.; Martinez Pillet, Valentin; Goode, Philip
   R.; Knoelker, Michael; Kuhn, Jeffrey Richard; Rosner, Robert; Casini,
   Roberto; Lin, Haosheng; von der Luehe, Oskar; Woeger, Friedrich;
   Tritschler, Alexandra; Fehlmann, Andre; Jaeggli, Sarah A.; Schmidt,
   Wolfgang; De Wijn, Alfred; Rast, Mark; Harrington, David M.; Sueoka,
   Stacey R.; Beck, Christian; Schad, Thomas A.; Warner, Mark; McMullin,
   Joseph P.; Berukoff, Steven J.; Mathioudakis, Mihalis; DKIST Team
Bibcode: 2018AAS...23231601R
Altcode:
  The 4m Daniel K. Inouye Solar Telescope (DKIST) currently under
  construction on Haleakala, Maui will be the world’s largest solar
  telescope. Designed to meet the needs of critical high resolution and
  high sensitivity spectral and polarimetric observations of the sun,
  this facility will perform key observations of our nearest star that
  matters most to humankind. DKIST’s superb resolution and sensitivity
  will enable astronomers to address many of the fundamental problems
  in solar and stellar astrophysics, including the origin of stellar
  magnetism, the mechanisms of coronal heating and drivers of the
  solar wind, flares, coronal mass ejections and variability in solar
  and stellar output. DKIST will also address basic research aspects of
  Space Weather and help improve predictive capabilities. In combination
  with synoptic observations and theoretical modeling DKIST will unravel
  the many remaining mysteries of the Sun.The construction of DKIST is
  progressing on schedule with 80% of the facility complete. Operations
  are scheduled to begin early 2020. DKIST will replace the NSO
  facilities on Kitt Peak and Sac Peak with a national facility with
  worldwide unique capabilities. The design allows DKIST to operate as
  a coronagraph. Taking advantage of its large aperture and infrared
  polarimeters DKIST will be capable to routinely measure the currently
  illusive coronal magnetic fields. The state-of-the-art adaptive optics
  system provides diffraction limited imaging and the ability to resolve
  features approximately 20 km on the Sun. Achieving this resolution
  is critical for the ability to observe magnetic structures at their
  intrinsic, fundamental scales. Five instruments will be available at
  the start of operations, four of which will provide highly sensitive
  measurements of solar magnetic fields throughout the solar atmosphere
  - from the photosphere to the corona. The data from these instruments
  will be distributed to the world wide community via the NSO/DKIST data
  center located in Boulder. We present examples of science objectives
  and provide an overview of the facility and project status, including
  the ongoing efforts of the community to develop the critical science
  plan for the first 2-3 years of operations.

Title: Solar UV Molecular Hydrogen Fluorescence
Authors: Daw, Adrian Nigel; Jaeggli, Sarah Amelia; Judge, Philip G.;
   Roueff, Evelyne; Abgrall, Hervé
Bibcode: 2018tess.conf21706D
Altcode:
  Solar observations of ultraviolet molecular hydrogen lines indicate
  that H<SUB>2</SUB> emission forms in particular regions, selectively
  excited by bright UV transition region and chromospheric lines. IRIS
  frequently observes numerous H<SUB>2</SUB> lines during flares and
  smaller energetic events, but the diagnostic value of these lines for
  probing the structure of the solar atmosphere has heretofore remained
  largely unexploited. We present a synthesis method for H<SUB>2</SUB>
  emission, using 1-D non-LTE models sampling a broad range of temperature
  stratifications and input radiation conditions from the atmosphere
  above, and compare the results to observations by IRIS, SUMER and
  HRTS from 1205 to 1550 Å. Because opacity due to photoionization of
  silicon and other neutrals determines the depth to which UV radiation
  can penetrate to excite the H<SUB>2</SUB>, the majority of H<SUB>2</SUB>
  emission forms in a narrow region near the tau=1 opacity surface for
  the exciting UV radiation, generally coming from above. The success
  of this 1-D approach to modeling solar UV H<SUB>2</SUB> emission is
  illustrated by the identification of previously unidentified lines and
  upper levels. Applications of the observed emission and implications
  for solar atmospheric structure are discussed.

Title: Formation of the UV Spectrum of Molecular Hydrogen in the Sun
Authors: Jaeggli, S. A.; Judge, P. G.; Daw, A. N.
Bibcode: 2018ApJ...855..134J
Altcode: 2018arXiv180203779J
  Ultraviolet (UV) lines of molecular hydrogen have been observed in
  solar spectra for almost four decades, but the behavior of the molecular
  spectrum and its implications for solar atmospheric structure are not
  fully understood. Data from the High-Resolution Telescope Spectrometer
  (HRTS) instrument revealed that H<SUB>2</SUB> emission forms in
  particular regions, selectively excited by a bright UV transition
  region and chromospheric lines. We test the conditions under which
  H<SUB>2</SUB> emission can originate by studying non-LTE models,
  sampling a broad range of temperature stratifications and radiation
  conditions. Stratification plays the dominant role in determining
  the population densities of H<SUB>2</SUB>, which forms in greatest
  abundance near the continuum photosphere. However, opacity due to
  the photoionization of Si and other neutrals determines the depth to
  which UV radiation can penetrate to excite the H<SUB>2</SUB>. Thus
  the majority of H<SUB>2</SUB> emission forms in a narrow region,
  at about 650 km in standard one-dimensional (1D) models of the quiet
  Sun, near the τ = 1 opacity surface for the exciting UV radiation,
  generally coming from above. When irradiated from above using observed
  intensities of bright UV emission lines, detailed non-LTE calculations
  show that the spectrum of H<SUB>2</SUB> seen in the quiet-Sun Solar
  Ultraviolet Measurement of Emitted Radiation atlas spectrum and HRTS
  light-bridge spectrum can be satisfactorily reproduced in 1D stratified
  atmospheres, without including three-dimensional or time-dependent
  thermal structures. A detailed comparison to observations from 1205 to
  1550 Å is presented, and the success of this 1D approach to modeling
  solar UV H<SUB>2</SUB> emission is illustrated by the identification
  of previously unidentified lines and upper levels in HRTS spectra.

Title: Formation of the UV Spectrum of Molecular Hydrogen in the Sun
Authors: Jaeggli, S. A.; Judge, P. G.; Daw, A. N.
Bibcode: 2017AGUFMSH52B..01J
Altcode:
  UV lines of molecular hydrogen in the Sun have been observed for almost
  four decades, but the behavior of the spectra and their implications
  for solar atmospheric structure are not fully understood. Data from the
  HRTS instrument revealed that H2 emission forms in particular regions,
  selectively excited by bright UV transition region and chromospheric
  lines. We test the conditions under which H2 emission can originate
  by studying non-LTE models with increasingly complex temperature
  stratification. Stratification plays the dominant role in determining
  the population densities of H2, which can form in abundance only within
  about 700 km of the continuum photosphere where 3D and dynamic structure
  generally play secondary roles to stratification. When irradiated
  from above using observed intensities of bright UV emission lines,
  detailed non-LTE calculations show that the spectrum of H2 can be
  satisfactorily modeled in 1D stratified atmospheric models, with no
  need to invoke unusual 3D or time dependent thermal structures.

Title: Critical Infrared Science with the Daniel K. Inouye Solar
    Telescope
Authors: Schad, Thomas A.; Fehlmann, Andre; Jaeggli, Sarah A.; Kuhn,
   Jeffrey Richard; Lin, Haosheng; Penn, Matthew J.; Rimmele, Thomas R.;
   Woeger, Friedrich
Bibcode: 2017SPD....4811703S
Altcode:
  Critical science planning for early operations of the Daniel K. Inouye
  Solar Telescope is underway. With its large aperture, all-reflective
  telescope design, and advanced instrumentation, DKIST provides
  unprecedented access to the important infrared (IR) solar spectrum
  between 1 and 5 microns. Breakthrough IR capabilities in coronal
  polarimetry will sense the coronal magnetic field routinely for the
  first time. The increased Zeeman resolution near the photospheric
  opacity minimum will provide our deepest and most sensitive measurement
  of quiet sun and active region magnetic fields to date. High-sensitivity
  He I triplet polarimetry will dynamically probe the chromospheric
  magnetic field in fibrils, spicules, and filaments, while observations
  of molecular CO transitions will characterize the coolest regions
  of the solar atmosphere. When combined with the longer timescales
  of good atmospheric seeing compared with the visible, DKIST infrared
  diagnostics are expected to be mainstays of solar physics in the DKIST
  era. This paper will summarize the critical science areas addressed
  by DKIST infrared instrumentation and invite the community to further
  contribute to critical infrared science planning.

Title: Large Scale Coordination of Small Scale Structures
Authors: Kobelski, Adam; Tarr, Lucas A.; Jaeggli, Sarah A.; Savage,
   Sabrina
Bibcode: 2017SPD....4820005K
Altcode:
  Transient brightenings are ubiquitous features of the solar atmosphere
  across many length and energy scales, the most energetic of which
  manifest as large-class solar flares. Often, transient brightenings
  originate in regions of strong magnetic activity and create strong
  observable enhancements across wavelengths from X-ray to radio, with
  notable dynamics on timescales of seconds to hours.The coronal aspects
  of these brightenings have often been studied by way of EUV and X-ray
  imaging and spectra. These events are likely driven by photospheric
  activity (such as flux emergence) with the coronal brightenings
  originating largely from chromospheric ablation (evaporation). Until
  recently, chromospheric and transition region observations of these
  events have been limited. However, new observational capabilities have
  become available which significantly enhance our ability to understand
  the bi-directional flow of energy through the chromosphere between the
  photosphere and the corona.We have recently obtained a unique data set
  with which to study this flow of energy through the chromosphere via
  the Interface Region Imaging Spectrograph (IRIS), Hinode EUV Imaging
  Spectrometer (EIS), Hinode X-Ray Telescope (XRT), Hinode Solar Optical
  Telescope (SOT), Solar Dynamics Observatory (SDO) Atmospheric Imaging
  Assembly (AIA), SDO Helioseismic and Magnetic Imager (HMI), Nuclear
  Spectroscopic Telescope Array (NuStar), Atacama Large Millimeter Array
  (ALMA), and Interferometric BIdimensional Spectropolarimeter (IBIS)
  at the Dunn Solar Telescope (DST). This data set targets a small active
  area near disk center which was tracked simultaneously for approximately
  four hours. Within this region, many transient brightenings detected
  through multiple layers of the solar atmosphere. In this study, we
  combine the imaging data and use the spectra from EIS and IRIS to
  track flows from the photosphere (HMI, SOT) through the chromosphere
  and transition region (AIA, IBIS, IRIS, ALMA) into the corona (EIS,
  XRT, AIA).

Title: An Update on the Diffraction-Limited Near Infrared
    Spectropolarimeter for the Daniel K. Inouye Solar Telescope
Authors: Jaeggli, Sarah A.; Lin, Haosheng; Onaka, Peter; McGregor,
   Helen; Yamada, Hubert
Bibcode: 2017SPD....4811704J
Altcode:
  DL-NIRSP is an integral field imaging spectropolarimeter for
  photospheric, chromospheric, and coronal magnetic field studies
  which is currently under development by the University of Hawaii’s
  Institute for Astronomy as part of the first light instrument suite for
  DKIST. DL-NIRSP pairs a multi-slit fiber-optic image slicer with narrow
  bandpass isolation filters and large format detectors to achieve very
  high cadence observations in three simultaneous wavelength channels
  in the Visible-IR. Planned diagnostics at first light include Fe XI
  789.2 nm, Ca II 854.2 nm, Fe XIII 1074.7 nm, Si I/He I 1083.0 nm, Si
  X 1430.0 nm, and Fe I 1565.0 nm. More spectral lines will be added in
  the future. As the last stop in the DKIST light distribution system,
  DL-NIRSP will receive an AO corrected beam and will be able to operate
  simultaneously with the other visible light instruments. We provide an
  update on the current challenges and rewards yet to come with DL-NIRSP.

Title: The Magnetic Classification of Solar Active Regions 1992-2015
Authors: Jaeggli, S. A.; Norton, A. A.
Bibcode: 2016ApJ...820L..11J
Altcode: 2016arXiv160302552J
  The purpose of this Letter is to address a blindspot in our knowledge
  of solar active region (AR) statistics. To the best of our knowledge,
  there are no published results showing the variation of the Mount
  Wilson magnetic classifications as a function of solar cycle based
  on modern observations. We show statistics for all ARs reported in
  the daily Solar Region Summary from 1992 January 1 to 2015 December
  31. We find that the α and β class ARs (including all sub-groups,
  e.g., βγ, βδ) make up fractions of approximately 20% and 80% of
  the sample, respectively. This fraction is relatively constant during
  high levels of activity however, an increase in the α fraction to
  about 35% and and a decrease in the β fraction to about 65% can
  be seen near each solar minimum and are statistically significant
  at the 2σ level. Over 30% of all ARs observed during the years of
  solar maxima were appended with the classifications γ and/or δ,
  while these classifications account for only a fraction of a percent
  during the years near the solar minima. This variation in the AR
  types indicates that the formation of complex ARs may be due to the
  pileup of frequent emergence of magnetic flux during solar maximum,
  rather than the emergence of complex, monolithic flux structures.

Title: Multi-wavelength Study of a Delta-spot. I. A Region of Very
    Strong, Horizontal Magnetic Field
Authors: Jaeggli, S. A.
Bibcode: 2016ApJ...818...81J
Altcode: 2015arXiv151208463J
  Active region NOAA 11035 appeared in 2009 December, early in the new
  solar activity cycle. This region achieved a delta sunspot (δ spot)
  configuration when parasitic flux emerged near the rotationally
  leading magnetic polarity and traveled through the penumbra of the
  largest sunspot in the group. Both visible and infrared imaging
  spectropolarimetry of the magnetically sensitive Fe I line pairs at
  6302 and 15650 Å show large Zeeman splitting in the penumbra between
  the parasitic umbra and the main sunspot umbra. The polarized Stokes
  spectra in the strongest field region display anomalous profiles,
  and strong blueshifts are seen in an adjacent region. Analysis of
  the profiles is carried out using a Milne-Eddington inversion code
  capable of fitting either a single magnetic component with stray
  light or two independent magnetic components to verify the field
  strength. The inversion results show that the anomalous profiles cannot
  be produced by the combination of two profiles with moderate magnetic
  fields. The largest field strengths are 3500-3800 G in close proximity
  to blueshifts as strong as 3.8 km s<SUP>-1</SUP>. The strong, nearly
  horizontal magnetic field seen near the polarity inversion line in
  this region is difficult to understand in the context of a standard
  model of sunspot magnetohydrostatic equilibrium.

Title: The Persistence of Apparent Non-Magnetostatic Equilibrium in
    NOAA 11035
Authors: Jaeggli, Sarah A.
Bibcode: 2015IAUS..305...35J
Altcode: 2015arXiv150401325J
  NOAA 11035 was a highly sheared active region that appeared in
  December 2009 early in the new activity cycle. The leading polarity
  sunspot developed a highly unusual feature in its penumbra, an
  opposite polarity pore with a strong magnetic field in excess of
  3500 G along one edge, which persisted for several days during the
  evolution of the region. This region was well observed by both space-
  and ground-based observatories, including Hinode, FIRS, TRACE, and
  SOHO. These observations, which span wavelength and atmospheric regimes,
  provide a complete picture of this unusual feature which may constitute
  a force-free magnetic field in the photosphere which is produced by
  the reconnection of magnetic loops low in the solar atmosphere.

Title: A very strong magnetic field region in NOAA 11035
Authors: Jaeggli, Sarah Amelia
Bibcode: 2015TESS....111304J
Altcode:
  NOAA 11035 was a fairly typical active region that emerged near
  the central meridian 13-14 December 2009, early in solar cycle
  24. During the active region’s rapid emergence and evolution, a
  deeply-rooted magnetic bipole emerged into the pre-existing leading
  polarity with spectacular consequences. Multi-wavelength imaging and
  spectropolarimetry from FIRS, IBIS, Hinode, TRACE, and SOHO allow
  for a comprehensive investigation of the physical processes present
  in this region. Intrusion of the opposite polarity into the leading
  sunspot’s penumbra resulted in a region of highly concentrated
  horizontal magnetic field, with a peak field strength larger than 3600
  G based on Milne-Eddington inversion of Fe I spectropolarimetry at
  6302 and 15650 Å. Photospheric velocity measurements show blueshifts
  of 4 km/sec along the neutral line, which are coincident with a dark
  chromospheric structure in He I 10830 and H I 6563 Å. We conclude that
  these signatures are the result of continuous magnetic reconnection
  near photospheric heights.

Title: Internetwork Chromospheric Bright Grains Observed With IRIS
    and SST
Authors: Martínez-Sykora, Juan; Rouppe van der Voort, Luc; Carlsson,
   Mats; De Pontieu, Bart; Pereira, Tiago M. D.; Boerner, Paul; Hurlburt,
   Neal; Kleint, Lucia; Lemen, James; Tarbell, Ted D.; Title, Alan;
   Wuelser, Jean-Pierre; Hansteen, Viggo H.; Golub, Leon; McKillop, Sean;
   Reeves, Kathy K.; Saar, Steven; Testa, Paola; Tian, Hui; Jaeggli,
   Sarah; Kankelborg, Charles
Bibcode: 2015ApJ...803...44M
Altcode: 2015arXiv150203490M
  The Interface Region Imaging Spectrograph (IRIS) reveals small-scale
  rapid brightenings in the form of bright grains all over coronal holes
  and the quiet Sun. These bright grains are seen with the IRIS 1330,
  1400, and 2796 Å slit-jaw filters. We combine coordinated observations
  with IRIS and from the ground with the Swedish 1 m Solar Telescope
  (SST) which allows us to have chromospheric (Ca ii 8542 Å, Ca ii H
  3968 Å, Hα, and Mg ii k 2796 Å) and transition region (C ii 1334 Å,
  Si iv 1403 Å) spectral imaging, and single-wavelength Stokes maps
  in Fe i 6302 Å at high spatial (0\buildrel{\prime\prime}\over{.}
  33), temporal, and spectral resolution. We conclude that the IRIS
  slit-jaw grains are the counterpart of so-called acoustic grains,
  i.e., resulting from chromospheric acoustic waves in a non-magnetic
  environment. We compare slit-jaw images (SJIs) with spectra from the
  IRIS spectrograph. We conclude that the grain intensity in the 2796
  Å slit-jaw filter comes from both the Mg ii k core and wings. The
  signal in the C ii and Si iv lines is too weak to explain the presence
  of grains in the 1300 and 1400 Å SJIs and we conclude that the grain
  signal in these passbands comes mostly from the continuum. Although
  weak, the characteristic shock signatures of acoustic grains can often
  be detected in IRIS C ii spectra. For some grains, a spectral signature
  can be found in IRIS Si iv. This suggests that upward propagating
  acoustic waves sometimes reach all the way up to the transition region.

Title: Homologous Helical Jets: Observations By IRIS, SDO, and Hinode
    and Magnetic Modeling With Data-Driven Simulations
Authors: Cheung, Mark C. M.; De Pontieu, B.; Tarbell, T. D.; Fu, Y.;
   Tian, H.; Testa, P.; Reeves, K. K.; Martínez-Sykora, J.; Boerner,
   P.; Wülser, J. P.; Lemen, J.; Title, A. M.; Hurlburt, N.; Kleint,
   L.; Kankelborg, C.; Jaeggli, S.; Golub, L.; McKillop, S.; Saar, S.;
   Carlsson, M.; Hansteen, V.
Bibcode: 2015ApJ...801...83C
Altcode: 2015arXiv150101593C
  We report on observations of recurrent jets by instruments on board
  the Interface Region Imaging Spectrograph, Solar Dynamics Observatory
  (SDO), and Hinode spacecraft. Over a 4 hr period on 2013 July 21,
  recurrent coronal jets were observed to emanate from NOAA Active Region
  11793. Far-ultraviolet spectra probing plasma at transition region
  temperatures show evidence of oppositely directed flows with components
  reaching Doppler velocities of ±100 km s<SUP>-1</SUP>. Raster Doppler
  maps using a Si iv transition region line show all four jets to have
  helical motion of the same sense. Simultaneous observations of the
  region by SDO and Hinode show that the jets emanate from a source
  region comprising a pore embedded in the interior of a supergranule. The
  parasitic pore has opposite polarity flux compared to the surrounding
  network field. This leads to a spine-fan magnetic topology in the
  coronal field that is amenable to jet formation. Time-dependent
  data-driven simulations are used to investigate the underlying drivers
  for the jets. These numerical experiments show that the emergence of
  current-carrying magnetic field in the vicinity of the pore supplies
  the magnetic twist needed for recurrent helical jet formation.

Title: The 2014 March 29 X-flare: Subarcsecond Resolution Observations
    of Fe XXI λ1354.1
Authors: Young, Peter R.; Tian, Hui; Jaeggli, Sarah
Bibcode: 2015ApJ...799..218Y
Altcode: 2014arXiv1409.8603Y
  The Interface Region Imaging Spectrometer (IRIS) is the first solar
  instrument to observe ~10 MK plasma at subarcsecond spatial resolution
  through imaging spectroscopy of the Fe XXI λ1354.1 forbidden line. IRIS
  observations of the X1 class flare that occurred on 2014 March 29 at
  17:48 UT reveal Fe XXI emission from both the flare ribbons and the
  post-flare loop arcade. Fe XXI appears at all of the chromospheric
  ribbon sites, although typically with a delay of one raster (75 s) and
  sometimes offset by up to 1''. 100-200 km s<SUP>-1</SUP> blue-shifts
  are found at the brightest ribbons, suggesting hot plasma upflow into
  the corona. The Fe XXI ribbon emission is compact with a spatial
  extent of &lt;2'', and can extend beyond the chromospheric ribbon
  locations. Examples are found of both decreasing and increasing
  blue-shift in the direction away from the ribbon locations, and
  blue-shifts were present for at least six minutes after the flare
  peak. The post-flare loop arcade, seen in Atmospheric Imaging Assembly
  131 Å filtergram images that are dominated by Fe XXI, exhibited
  bright loop-tops with an asymmetric intensity distribution. The sizes
  of the loop-tops are resolved by IRIS at &gt;=1'', and line widths
  in the loop-tops are not broader than in the loop-legs suggesting the
  loop-tops are not sites of enhanced turbulence. Line-of-sight speeds
  in the loop arcade are typically &lt;10 km s<SUP>-1</SUP>, and mean
  non-thermal motions fall from 43 km s<SUP>-1</SUP> at the flare peak
  to 26 km s<SUP>-1</SUP> six minutes later. If the average velocity
  in the loop arcade is assumed to be at rest, then it implies a new
  reference wavelength for the Fe XXI line of 1354.106 ± 0.023 Å.

Title: Venus' thermospheric temperature field using a refraction
model at terminator : comparison with 2012 transit observations
    using SDO/HMI, VEx/SPICAV/SOIR and NSO/DST/FIRS
Authors: Widemann, Thomas; Jaeggli, Sarah; Reardon, Kevin; Tanga,
   Paolo; Père, Christophe; Pasachoff, Jay M.; Vandaele, Ann Carine;
   Wilquet, Valerie; Mahieux, Arnaud; Wilson, Colin
Bibcode: 2014DPS....4630206W
Altcode:
  The transit of Venus in June 2012 provided a unique case study of the
  Venus' atmosphere transiting in front of the Sun, while at the same time
  ESA's Venus Express orbiter observed the evening terminator at solar
  ingress and solar egress.We report on mesospheric temperature at Venus'
  morning terminator using SDO/HMI aureole photometry and comparison with
  Venus Express. Close to ingress and egress phases, we have shown that
  the aureole photometry reflects the local density scale height and the
  altitude of the refracting layer (Tanga et al. 2012). The lightcurve of
  each spatially resolved aureole element is fit to a two-parameter model
  to constrain the meridional temperature gradient at terminator. Our
  measurements are in agreement with the VEx/SOIR temperatures obtained
  during orbit 2238 at evening terminator during solar ingress (46.75N -
  LST = 6.075PM) and solar egress (31.30N - LST = 6.047PM) captured from
  the Venus Express orbiter at the time Venus transited the Sun.We also
  performed spectroscopy and polarimetry during the transit of Venus
  focusing on extracting signatures of CO2 absorption. Observations were
  taken during the first half of the transit using the Facility InfraRed
  Spectropolarimeter (FIRS) on the Dunn Solar Telescope (DST). Although
  the predicted CO2 transmission spectrum of Venus was not particularly
  strong at 1565 nm, this region of the H-band often used in magnetic
  field studies of the Sun's photosphere provides a particularly flat
  solar continuum with few atmospheric lines. Sun-subtracted Venus limb
  observations show intensity distribution of vibrational CO2 bands 221
  2v+2v2+v3 at 1.571μm and 141 v1+4v2+v3 at 1.606μm.

Title: Hot explosions in the cool atmosphere of the Sun
Authors: Peter, H.; Tian, H.; Curdt, W.; Schmit, D.; Innes, D.;
   De Pontieu, B.; Lemen, J.; Title, A.; Boerner, P.; Hurlburt, N.;
   Tarbell, T. D.; Wuelser, J. P.; Martínez-Sykora, Juan; Kleint,
   L.; Golub, L.; McKillop, S.; Reeves, K. K.; Saar, S.; Testa, P.;
   Kankelborg, C.; Jaeggli, S.; Carlsson, M.; Hansteen, V.
Bibcode: 2014Sci...346C.315P
Altcode: 2014arXiv1410.5842P
  The solar atmosphere was traditionally represented with a simple
  one-dimensional model. Over the past few decades, this paradigm shifted
  for the chromosphere and corona that constitute the outer atmosphere,
  which is now considered a dynamic structured envelope. Recent
  observations by the Interface Region Imaging Spectrograph (IRIS) reveal
  that it is difficult to determine what is up and down, even in the cool
  6000-kelvin photosphere just above the solar surface: This region hosts
  pockets of hot plasma transiently heated to almost 100,000 kelvin. The
  energy to heat and accelerate the plasma requires a considerable
  fraction of the energy from flares, the largest solar disruptions. These
  IRIS observations not only confirm that the photosphere is more complex
  than conventionally thought, but also provide insight into the energy
  conversion in the process of magnetic reconnection.

Title: The unresolved fine structure resolved: IRIS observations of
    the solar transition region
Authors: Hansteen, V.; De Pontieu, B.; Carlsson, M.; Lemen, J.; Title,
   A.; Boerner, P.; Hurlburt, N.; Tarbell, T. D.; Wuelser, J. P.; Pereira,
   T. M. D.; De Luca, E. E.; Golub, L.; McKillop, S.; Reeves, K.; Saar,
   S.; Testa, P.; Tian, H.; Kankelborg, C.; Jaeggli, S.; Kleint, L.;
   Martínez-Sykora, J.
Bibcode: 2014Sci...346E.315H
Altcode: 2014arXiv1412.3611H
  The heating of the outer solar atmospheric layers, i.e., the transition
  region and corona, to high temperatures is a long-standing problem
  in solar (and stellar) physics. Solutions have been hampered by an
  incomplete understanding of the magnetically controlled structure of
  these regions. The high spatial and temporal resolution observations
  with the Interface Region Imaging Spectrograph (IRIS) at the solar
  limb reveal a plethora of short, low-lying loops or loop segments
  at transition-region temperatures that vary rapidly, on the time
  scales of minutes. We argue that the existence of these loops solves
  a long-standing observational mystery. At the same time, based on
  comparison with numerical models, this detection sheds light on a
  critical piece of the coronal heating puzzle.

Title: Evidence of nonthermal particles in coronal loops heated
    impulsively by nanoflares
Authors: Testa, P.; De Pontieu, B.; Allred, J.; Carlsson, M.; Reale,
   F.; Daw, A.; Hansteen, V.; Martinez-Sykora, J.; Liu, W.; DeLuca, E. E.;
   Golub, L.; McKillop, S.; Reeves, K.; Saar, S.; Tian, H.; Lemen, J.;
   Title, A.; Boerner, P.; Hurlburt, N.; Tarbell, T. D.; Wuelser, J. P.;
   Kleint, L.; Kankelborg, C.; Jaeggli, S.
Bibcode: 2014Sci...346B.315T
Altcode: 2014arXiv1410.6130T
  The physical processes causing energy exchange between the Sun’s
  hot corona and its cool lower atmosphere remain poorly understood. The
  chromosphere and transition region (TR) form an interface region between
  the surface and the corona that is highly sensitive to the coronal
  heating mechanism. High-resolution observations with the Interface
  Region Imaging Spectrograph (IRIS) reveal rapid variability (~20 to
  60 seconds) of intensity and velocity on small spatial scales (≲500
  kilometers) at the footpoints of hot and dynamic coronal loops. The
  observations are consistent with numerical simulations of heating by
  beams of nonthermal electrons, which are generated in small impulsive
  (≲30 seconds) heating events called “coronal nanoflares.” The
  accelerated electrons deposit a sizable fraction of their energy
  (≲10<SUP>25 </SUP>erg) in the chromosphere and TR. Our analysis
  provides tight constraints on the properties of such electron beams
  and new diagnostics for their presence in the nonflaring corona.

Title: Prevalence of small-scale jets from the networks of the solar
    transition region and chromosphere
Authors: Tian, H.; DeLuca, E. E.; Cranmer, S. R.; De Pontieu, B.;
   Peter, H.; Martínez-Sykora, J.; Golub, L.; McKillop, S.; Reeves,
   K. K.; Miralles, M. P.; McCauley, P.; Saar, S.; Testa, P.; Weber,
   M.; Murphy, N.; Lemen, J.; Title, A.; Boerner, P.; Hurlburt, N.;
   Tarbell, T. D.; Wuelser, J. P.; Kleint, L.; Kankelborg, C.; Jaeggli,
   S.; Carlsson, M.; Hansteen, V.; McIntosh, S. W.
Bibcode: 2014Sci...346A.315T
Altcode: 2014arXiv1410.6143T
  As the interface between the Sun’s photosphere and corona, the
  chromosphere and transition region play a key role in the formation and
  acceleration of the solar wind. Observations from the Interface Region
  Imaging Spectrograph reveal the prevalence of intermittent small-scale
  jets with speeds of 80 to 250 kilometers per second from the narrow
  bright network lanes of this interface region. These jets have lifetimes
  of 20 to 80 seconds and widths of ≤300 kilometers. They originate from
  small-scale bright regions, often preceded by footpoint brightenings
  and accompanied by transverse waves with amplitudes of ~20 kilometers
  per second. Many jets reach temperatures of at least ~10<SUP>5</SUP>
  kelvin and constitute an important element of the transition region
  structures. They are likely an intermittent but persistent source of
  mass and energy for the solar wind.

Title: On the prevalence of small-scale twist in the solar
    chromosphere and transition region
Authors: De Pontieu, B.; Rouppe van der Voort, L.; McIntosh, S. W.;
   Pereira, T. M. D.; Carlsson, M.; Hansteen, V.; Skogsrud, H.; Lemen,
   J.; Title, A.; Boerner, P.; Hurlburt, N.; Tarbell, T. D.; Wuelser,
   J. P.; De Luca, E. E.; Golub, L.; McKillop, S.; Reeves, K.; Saar,
   S.; Testa, P.; Tian, H.; Kankelborg, C.; Jaeggli, S.; Kleint, L.;
   Martinez-Sykora, J.
Bibcode: 2014Sci...346D.315D
Altcode: 2014arXiv1410.6862D
  The solar chromosphere and transition region (TR) form an interface
  between the Sun’s surface and its hot outer atmosphere. There,
  most of the nonthermal energy that powers the solar atmosphere
  is transformed into heat, although the detailed mechanism remains
  elusive. High-resolution (0.33-arc second) observations with NASA’s
  Interface Region Imaging Spectrograph (IRIS) reveal a chromosphere
  and TR that are replete with twist or torsional motions on sub-arc
  second scales, occurring in active regions, quiet Sun regions, and
  coronal holes alike. We coordinated observations with the Swedish
  1-meter Solar Telescope (SST) to quantify these twisting motions and
  their association with rapid heating to at least TR temperatures. This
  view of the interface region provides insight into what heats the low
  solar atmosphere.

Title: An Interface Region Imaging Spectrograph First View on Solar
    Spicules
Authors: Pereira, T. M. D.; De Pontieu, B.; Carlsson, M.; Hansteen,
   V.; Tarbell, T. D.; Lemen, J.; Title, A.; Boerner, P.; Hurlburt,
   N.; Wülser, J. P.; Martínez-Sykora, J.; Kleint, L.; Golub, L.;
   McKillop, S.; Reeves, K. K.; Saar, S.; Testa, P.; Tian, H.; Jaeggli,
   S.; Kankelborg, C.
Bibcode: 2014ApJ...792L..15P
Altcode: 2014arXiv1407.6360P
  Solar spicules have eluded modelers and observers for decades. Since
  the discovery of the more energetic type II, spicules have become
  a heated topic but their contribution to the energy balance of the
  low solar atmosphere remains unknown. Here we give a first glimpse of
  what quiet-Sun spicules look like when observed with NASA's recently
  launched Interface Region Imaging Spectrograph (IRIS). Using IRIS
  spectra and filtergrams that sample the chromosphere and transition
  region, we compare the properties and evolution of spicules as
  observed in a coordinated campaign with Hinode and the Atmospheric
  Imaging Assembly. Our IRIS observations allow us to follow the thermal
  evolution of type II spicules and finally confirm that the fading
  of Ca II H spicules appears to be caused by rapid heating to higher
  temperatures. The IRIS spicules do not fade but continue evolving,
  reaching higher and falling back down after 500-800 s. Ca II H type
  II spicules are thus the initial stages of violent and hotter events
  that mostly remain invisible in Ca II H filtergrams. These events
  have very different properties from type I spicules, which show lower
  velocities and no fading from chromospheric passbands. The IRIS spectra
  of spicules show the same signature as their proposed disk counterparts,
  reinforcing earlier work. Spectroheliograms from spectral rasters also
  confirm that quiet-Sun spicules originate in bushes from the magnetic
  network. Our results suggest that type II spicules are indeed the
  site of vigorous heating (to at least transition region temperatures)
  along extensive parts of the upward moving spicular plasma.

Title: Molecular absorption in transition region spectral lines
Authors: Schmit, D. J.; Innes, D.; Ayres, T.; Peter, H.; Curdt, W.;
   Jaeggli, S.
Bibcode: 2014A&A...569L...7S
Altcode: 2014arXiv1409.1702S
  <BR /> Aims: We present observations from the Interface Region Imaging
  Spectrograph (IRIS) of absorption features from a multitude of cool
  atomic and molecular lines within the profiles of Si IV transition
  region lines. Many of these spectral lines have not previously
  been detected in solar spectra. <BR /> Methods: We examined spectra
  taken from deep exposures of plage on 12 October 2013. We observed
  unique absorption spectra over a magnetic element which is bright in
  transition region line emission and the ultraviolet continuum. We
  compared the absorption spectra with emission spectra that is
  likely related to fluorescence. <BR /> Results: The absorption
  features require a population of sub-5000 K plasma to exist above
  the transition region. This peculiar stratification is an extreme
  deviation from the canonical structure of the chromosphere-corona
  boundary. The cool material is not associated with a filament or
  discernible coronal rain. This suggests that molecules may form in
  the upper solar atmosphere on small spatial scales and introduces a
  new complexity into our understanding of solar thermal structure. It
  lends credence to previous numerical studies that found evidence
  for elevated pockets of cool gas in the chromosphere. <P />Movies
  associated to Figs. 1 and 2 are available in electronic form at <A
  href="http://www.aanda.org/10.1051/0004-6361/201424432/olm">http://www.aanda.org</A>

Title: The Interface Region Imaging Spectrograph (IRIS)
Authors: De Pontieu, B.; Title, A. M.; Lemen, J. R.; Kushner, G. D.;
   Akin, D. J.; Allard, B.; Berger, T.; Boerner, P.; Cheung, M.; Chou,
   C.; Drake, J. F.; Duncan, D. W.; Freeland, S.; Heyman, G. F.; Hoffman,
   C.; Hurlburt, N. E.; Lindgren, R. W.; Mathur, D.; Rehse, R.; Sabolish,
   D.; Seguin, R.; Schrijver, C. J.; Tarbell, T. D.; Wülser, J. -P.;
   Wolfson, C. J.; Yanari, C.; Mudge, J.; Nguyen-Phuc, N.; Timmons,
   R.; van Bezooijen, R.; Weingrod, I.; Brookner, R.; Butcher, G.;
   Dougherty, B.; Eder, J.; Knagenhjelm, V.; Larsen, S.; Mansir, D.;
   Phan, L.; Boyle, P.; Cheimets, P. N.; DeLuca, E. E.; Golub, L.;
   Gates, R.; Hertz, E.; McKillop, S.; Park, S.; Perry, T.; Podgorski,
   W. A.; Reeves, K.; Saar, S.; Testa, P.; Tian, H.; Weber, M.; Dunn, C.;
   Eccles, S.; Jaeggli, S. A.; Kankelborg, C. C.; Mashburn, K.; Pust, N.;
   Springer, L.; Carvalho, R.; Kleint, L.; Marmie, J.; Mazmanian, E.;
   Pereira, T. M. D.; Sawyer, S.; Strong, J.; Worden, S. P.; Carlsson,
   M.; Hansteen, V. H.; Leenaarts, J.; Wiesmann, M.; Aloise, J.; Chu,
   K. -C.; Bush, R. I.; Scherrer, P. H.; Brekke, P.; Martinez-Sykora,
   J.; Lites, B. W.; McIntosh, S. W.; Uitenbroek, H.; Okamoto, T. J.;
   Gummin, M. A.; Auker, G.; Jerram, P.; Pool, P.; Waltham, N.
Bibcode: 2014SoPh..289.2733D
Altcode: 2014arXiv1401.2491D; 2014SoPh..tmp...25D
  The Interface Region Imaging Spectrograph (IRIS) small explorer
  spacecraft provides simultaneous spectra and images of the photosphere,
  chromosphere, transition region, and corona with 0.33 - 0.4 arcsec
  spatial resolution, two-second temporal resolution, and 1 km
  s<SUP>−1</SUP> velocity resolution over a field-of-view of up to
  175 arcsec × 175 arcsec. IRIS was launched into a Sun-synchronous
  orbit on 27 June 2013 using a Pegasus-XL rocket and consists of a
  19-cm UV telescope that feeds a slit-based dual-bandpass imaging
  spectrograph. IRIS obtains spectra in passbands from 1332 - 1358 Å,
  1389 - 1407 Å, and 2783 - 2834 Å, including bright spectral lines
  formed in the chromosphere (Mg II h 2803 Å and Mg II k 2796 Å) and
  transition region (C II 1334/1335 Å and Si IV 1394/1403 Å). Slit-jaw
  images in four different passbands (C II 1330, Si IV 1400, Mg II k
  2796, and Mg II wing 2830 Å) can be taken simultaneously with spectral
  rasters that sample regions up to 130 arcsec × 175 arcsec at a variety
  of spatial samplings (from 0.33 arcsec and up). IRIS is sensitive to
  emission from plasma at temperatures between 5000 K and 10 MK and will
  advance our understanding of the flow of mass and energy through an
  interface region, formed by the chromosphere and transition region,
  between the photosphere and corona. This highly structured and dynamic
  region not only acts as the conduit of all mass and energy feeding
  into the corona and solar wind, it also requires an order of magnitude
  more energy to heat than the corona and solar wind combined. The
  IRIS investigation includes a strong numerical modeling component
  based on advanced radiative-MHD codes to facilitate interpretation of
  observations of this complex region. Approximately eight Gbytes of data
  (after compression) are acquired by IRIS each day and made available
  for unrestricted use within a few days of the observation.

Title: Detection of Supersonic Downflows and Associated Heating
    Events in the Transition Region above Sunspots
Authors: Kleint, L.; Antolin, P.; Tian, H.; Judge, P.; Testa, P.;
   De Pontieu, B.; Martínez-Sykora, J.; Reeves, K. K.; Wuelser, J. P.;
   McKillop, S.; Saar, S.; Carlsson, M.; Boerner, P.; Hurlburt, N.; Lemen,
   J.; Tarbell, T. D.; Title, A.; Golub, L.; Hansteen, V.; Jaeggli, S.;
   Kankelborg, C.
Bibcode: 2014ApJ...789L..42K
Altcode: 2014arXiv1406.6816K
  Interface Region Imaging Spectrograph data allow us to study the solar
  transition region (TR) with an unprecedented spatial resolution of
  0.''33. On 2013 August 30, we observed bursts of high Doppler shifts
  suggesting strong supersonic downflows of up to 200 km s<SUP>-1</SUP>
  and weaker, slightly slower upflows in the spectral lines Mg II h
  and k, C II 1336, Si IV 1394 Å, and 1403 Å, that are correlated
  with brightenings in the slitjaw images (SJIs). The bursty behavior
  lasts throughout the 2 hr observation, with average burst durations
  of about 20 s. The locations of these short-lived events appear to
  be the umbral and penumbral footpoints of EUV loops. Fast apparent
  downflows are observed along these loops in the SJIs and in the
  Atmospheric Imaging Assembly, suggesting that the loops are thermally
  unstable. We interpret the observations as cool material falling
  from coronal heights, and especially coronal rain produced along the
  thermally unstable loops, which leads to an increase of intensity
  at the loop footpoints, probably indicating an increase of density
  and temperature in the TR. The rain speeds are on the higher end of
  previously reported speeds for this phenomenon, and possibly higher
  than the free-fall velocity along the loops. On other observing days,
  similar bright dots are sometimes aligned into ribbons, resembling
  small flare ribbons. These observations provide a first insight into
  small-scale heating events in sunspots in the TR.

Title: Chromospheric Diagnostics from IRIS and DST
Authors: Cauzzi, Gianna; Reardon, Kevin P.; Jaeggli, Sarah A.;
   Reid, Aaron
Bibcode: 2014AAS...22430201C
Altcode:
  Using data obtained during a coordinated observing campaign in
  September 2013, we compare the spectral and imaging diagnostics from
  IRIS and the instruments at the Dunn Solar Telescope (DST). We focus
  on a small active region observed for approximately one hour with IRIS
  (NUV, FUV, and SJI) in conjunction with IBIS, FIRS, and ROSA from the
  DST.In particular, we examine the line widths and intensities in the
  different chromospheric lines (H-alpha, Ca II 8542, Mg II) and the
  temporal evolution of these different diagnostics. This allows us to
  better relate the views from new window provided by IRIS to previous
  studies of the chromosphere.

Title: Investigating Molecular Hydrogen in Active Regions with IRIS
Authors: Jaeggli, Sarah A.; Saar, Steven H.; Daw, Adrian N.; Innes,
   Davina
Bibcode: 2014AAS...22432306J
Altcode:
  Molecular hydrogen should be the most abundant molecular species in
  sunspots, but recent observations with IRIS show that its florescent
  signature is absent from above the sunspot umbra, but appears
  brightly during flares. In this poster we continue the analysis of
  FUV observations of H2 in active regions, examining the correlation
  between the intensity of the H2 lines and the lines of C II and
  Si IV which are responsible for their excitation. We particularly
  focus on differentiating places where H2 is abundant, holes in the
  chromospheric opacity where FUV photons can enter more deeply into the
  solar atmosphere, and places where the FUV radiation field is intense,
  as in flares.

Title: H2 Emission in the Sun and Stars: A New Window on Spots
    and Flares
Authors: Saar, Steven H.; Jaeggli, Sarah A.
Bibcode: 2014AAS...22412344S
Altcode:
  Molecular H2 is likely important for the formation of sun and starspots,
  but has been difficult to observe in the past. H2 emission has been
  seen in solar FUV spectra of sunspots and flares, where it produced
  by fluorescent excitation driven (primarily) by Si IV and O IV. New
  observations with IRIS show that the emission is strong in flares,
  and in loops connected to pores or the boundaries of umbrae. We find
  evidence for H2 emission in the HST spectra of several magnetically
  active, flaring, spotted stars. Once the excitation process is better
  understood, observations of H2 emission should permit new insight into
  spot formation on the Sun and active stars.

Title: Venus' thermospheric temperature field using a refraction
model at terminator : comparison with 2012 transit observations
    using SDO/HMI and NSO/DST/FIRS
Authors: Widemann, Thomas; Tanga, Paolo; Père, Christophe; Jaeggli,
   Sarah; Reardon, Kevin; Pasachoff, Jay M.
Bibcode: 2014EGUGA..1612916W
Altcode:
  The transit of Venus in June 2012 provided a unique case study of an
  Earth-size planet's atmosphere transiting in front of its parent star
  at 0.7AU, while at the same time ESA's Venus Express orbiter observed
  the evening terminator at solar ingress and solar egress. We report
  on mesospheric temperature at Venus' morning terminator using SDO/HMI
  aureole photometry and comparison with Venus Express. Close to ingress
  and egress phases, we have shown that the aureole photometry reflects
  the local density scale height and the altitude of the refracting layer
  (Tanga et al. 2012). The lightcurve of each spatial resolution element
  of the aureole is compared to a two-parameter model to constrain the
  meridional temperature gradient along the terminator. Our measurements
  are in agreement with the VEx/SOIR temperatures obtained during
  orbit 2238 at evening terminator during solar ingress (46.75N - LST
  = 6.075PM) and solar egress (31.30N - LST = 6.047PM) captured from
  the Venus Express orbiter at the time Venus transited the Sun for
  Earth-based observers. We also performed spectroscopy and polarimetry
  during the transit of Venus focusing on extracting signatures of
  CO2 absorption. Observations were taken during the first half of the
  transit using the Facility InfraRed Spectropolarimeter on the Dunn
  Solar Telescope. Although the predicted CO2 transmission spectrum
  of Venus was not particularly strong at 1565 nm, this region of the
  H-band often used in magnetic field studies of the Sun's photosphere
  provides a particularly flat solar continuum with few atmospheric and
  molecular lines. Sun-subtracted Venus limb observations show intensity
  distribution of vibrational CO2 bands 221 2v + 2ν2 + ν3 at 1.571um and
  141 ν1 + 4ν2 + ν3 at 1.606um. Data independently allow to constrain
  temperature as well as cross-terminator thermospheric winds.

Title: High-resolution Observations of the Shock Wave Behavior for
    Sunspot Oscillations with the Interface Region Imaging Spectrograph
Authors: Tian, H.; DeLuca, E.; Reeves, K. K.; McKillop, S.; De Pontieu,
   B.; Martínez-Sykora, J.; Carlsson, M.; Hansteen, V.; Kleint, L.;
   Cheung, M.; Golub, L.; Saar, S.; Testa, P.; Weber, M.; Lemen, J.;
   Title, A.; Boerner, P.; Hurlburt, N.; Tarbell, T. D.; Wuelser, J. P.;
   Kankelborg, C.; Jaeggli, S.; McIntosh, S. W.
Bibcode: 2014ApJ...786..137T
Altcode: 2014arXiv1404.6291T
  We present the first results of sunspot oscillations from observations
  by the Interface Region Imaging Spectrograph. The strongly nonlinear
  oscillation is identified in both the slit-jaw images and the
  spectra of several emission lines formed in the transition region and
  chromosphere. We first apply a single Gaussian fit to the profiles of
  the Mg II 2796.35 Å, C II 1335.71 Å, and Si IV 1393.76 Å lines in the
  sunspot. The intensity change is ~30%. The Doppler shift oscillation
  reveals a sawtooth pattern with an amplitude of ~10 km s<SUP>-1</SUP>
  in Si IV. The Si IV oscillation lags those of C II and Mg II by ~3 and
  ~12 s, respectively. The line width suddenly increases as the Doppler
  shift changes from redshift to blueshift. However, we demonstrate
  that this increase is caused by the superposition of two emission
  components. We then perform detailed analysis of the line profiles at
  a few selected locations on the slit. The temporal evolution of the
  line core is dominated by the following behavior: a rapid excursion
  to the blue side, accompanied by an intensity increase, followed by a
  linear decrease of the velocity to the red side. The maximum intensity
  slightly lags the maximum blueshift in Si IV, whereas the intensity
  enhancement slightly precedes the maximum blueshift in Mg II. We find
  a positive correlation between the maximum velocity and deceleration,
  a result that is consistent with numerical simulations of upward
  propagating magnetoacoustic shock waves.

Title: Characterization of a transiting exo-Venus : lessons from
    the 2012 Transit
Authors: Widemann, Thomas; Jaeggli, S. A.; Reardon, K. P.; Tanga,
   P.; Pasachoff, J. M.; Schneider, G.
Bibcode: 2013DPS....4511811W
Altcode:
  The transit of Venus in June 2012 provided a unique chance to
  view a well studied planetary atmosphere as we might see that of a
  transiting exoplanet, through scattered and refracted illumination
  of its parent star. We report on mesospheric temperature at Venus'
  morning terminator using SDO/HMI aureole photometry and comparison with
  Venus Express. Close to ingress and egress phases, we have shown that
  the aureole photometry reflects the local density scale height and the
  altitude of the refracting layer (Tanga et al. 2012). The lightcurve
  of each spatial resolution element of the aureole is compared to a
  two-parameter model to constrain the meridional temperature gradient
  along the terminator. Our measurements are in agreement with the
  VEx/SOIR temperatures obtained during orbit 2238 at evening terminator
  during solar ingress (46.75N - LST = 6.075PM) and solar egress (31.30N -
  LST = 6.047PM) as seen from the orbiter. Imaging data using IBIS/ROSA on
  the Dunn Solar Telescope in the G-band (430 nm) are also presented. We
  also performed spectroscopy and polarimetry during the transit of Venus
  focusing on extracting signatures of CO2 absorption. Observations were
  taken during the first half of the transit using the Facility InfraRed
  Spectropolarimeter on the Dunn Solar Telescope. Although the predicted
  CO2 transmission spectrum of Venus was not particularly strong at 1565
  nm, this region of the H-band often used in magnetic field studies of
  the Sun's photosphere provides a particularly flat solar continuum
  with few atmospheric and molecular lines. Sun-subtracted Venus limb
  observations show intensity distribution of vibro-rotational CO2 band
  221 2ν + 2ν2 + ν3 at 1.571μm allowing for an additional constraint
  on Venus' thermospheric temperature.

Title: Testing Milne-Eddington Inversion Codes Against One-Dimensional
    Model Atmospheres
Authors: Lastufka, Erica; Jaeggli, S. A.; Kankelborg, C.; Uitenbroek,
   H.
Bibcode: 2013SPD....44..116L
Altcode:
  Properties of solar vector magnetic fields can be determined by the
  inversion of polarization spectra. It is therefore important to have
  accurate inversion methods. Milne-Eddington inversions, used almost
  exclusively in the photosphere, assume a thin, flat atmosphere and are
  one of the most widely used inversion techniques. To investigate the
  potential weaknesses of parameterizing a stratified atmosphere using
  a single set of properties, we examine the consequences of using a
  Milne-Eddington inversion to invert spectra of complex atmospheres. Han
  Uitenbroek's Rybicki-Hummer radiative transfer and chemical equilibrium
  code was used to generate a series of one-dimensional model atmospheres
  with predetermined magnetic field configurations. Atmospheres at the
  quiet Sun temperature contained magnetic fields with strengths up
  3000 G and inclination and azimuthal angles from 0 to 180 degrees. We
  examined the Stokes profiles of the Fe 15648.5 line, which with a
  Landé g-factor of 3.0 is very sensitive to the magnetic field. Using a
  simple Milne-Eddington inversion code, we examined the ranges in which
  the code accurately parameterized the magnetic field. To investigate
  the confidence intervals associated with the inverted parameters, we
  used the BayesME code developed by Andres Asensio Ramos. We discuss
  the key assumptions and limitations of a Milne-Eddington inversion.

Title: Supernova 2013do in UGC 12137 = Psn J22395067+3812443
Authors: Elenin, L.; Molotov, I.; Rachubo, A. A.; Leonard, D. C.;
   Follette, K.; Sheehan, P.; McCarthy, D.; Moustakas, J.; Bailey, V.;
   Barrows, J.; Bosset, E.; Buckley, E.; Burd, D.; Calahan, J.; Ceesay,
   I.; Douglas, E.; Feeney, C.; Fornari, T.; Fox, A.; Fishwick, H.;
   Gano, H.; Green, C.; Griggs, J.; Hart, K.; Hart, S.; Hartman, K.;
   Holt, A.; Hooper, E.; Hume, S.; Jaeggli, S.; Lesser, D.; Kerr, M.;
   Kopans-Johnson, C.; Kumar, K.; Lackey, A.; Laube, S.; Marshall, E.;
   Martinez, M.; Mehta, G.; Melbourne, K.; Meshel, M.; Myers, C.; Puranen,
   E.; Schlingman, A.; Shen, K.; Stock, N.; Stillman, C.; Tinker, J.;
   Whitesell, B.; Tinyanont, S.; Cao, Y.; Kasliwal, M. M.
Bibcode: 2013CBET.3571....2E
Altcode:
  Additional CCD magnitudes for 2013do: 2013 June 1, [19.0
  (Wang and Gao); 17.763, 17.0 (Joseph Brimacombe, Cairns,
  Australia; 41-cm telescope + infrared filter; bandpass &gt;
  700 nm; position end figures 50s.65, 43".5; image posted at URL
  http://www.flickr.com/photos/43846774@N02/9074451038/); 18.253,
  18.1 (L. Elenin, Lyubertsy, Russia, and I. Molotov, Moscow;
  three 150-s images taken remotely with a 0.45-m f/2.8 telescope
  at the ISON-NM Observatory near Mayhill, NM, USA; position end
  figures 50s.54 +/- 0".18, 44".8 +/- 0".19; UCAC-4 reference
  stars; limiting mag about 18.8; image posted at website URL
  http://spaceobs.org/images/TOCP/PSNJ22395067+3812443-20130618.png);
  21.832, 17.2 (Wang and Gao; position end figures 50s.69, 44".3); 22.819,
  17.1 (Wang and Gao; position end figures 50s.70, 43".3). A. A. Rachubo
  and D. C. Leonard, San Diego State University; K. Follette, P. Sheehan,
  and D. McCarthy, University of Arizona; J. Moustakas, Siena College;
  V. Bailey, J. Barrows, E. Bosset, E. Buckley, D. Burd, J. Calahan,
  I. Ceesay, E. Douglas, C. Feeney, T. Fornari, A. Fox, H. Fishwick,
  H. Gano, C. Green, J. Griggs, K. Hart, S. Hart, K. Hartman, A. Holt,
  E. Hooper, S. Hume, S. Jaeggli, D. Lesser, M. Kerr, C. Kopans-Johnson,
  K. Kumar, A. Lackey, S. Laube, E. Marshall, M. Martinez, G. Mehta,
  K. Melbourne, M. Meshel, C. Myers, E. Puranen, A. Schlingman,
  W. Schlingman, W. M. Schlingman, K. Shen, N. Stock, C. Stillman,
  J. Tinker, and B. Whitesell, 2013 Advanced Teen Astronomy Camp, report
  that inspection of a low-dispersion optical spectrum (range 350-660
  nm) of PSN J22395067+3812443 = SN 2013do, obtained with the 2.3-m Bok
  telescope (+ Boller &amp; Chivens spectrograph) at Steward Observatory
  on June 26 UT, shows it to be a type-II supernova. Cross-correlation
  with a library of supernova spectra using the "Supernova Identification"
  code (SNID; Blondin and Tonry 2007, Ap.J. 666, 1024) finds best matches
  with a number of normal type-IIP supernovae ranging in age from about
  one to two weeks after maximum light. Adopting the recession velocity
  for UGC 12137 of 4685 km/s (Wegner et al. 1993, A.J. 105, 1251; via
  the NASA/IPAC Extragalactic Database), an expansion velocity of 8900
  km/s is derived from the position of the H_beta (rest wavelength 486.1
  nm) minimum. S. Tinyanont, Harvey Mudd College; Y. Cao, California
  Institute of Technology; and M. M. Kasliwal, Observatories of the
  Carnegie Institution and Princeton University, report that spectroscopic
  observations (range 330-1000 nm) of PSN J22395067+3812443 = SN 2013do
  were obtained on June 27.27 UT with the Dual Imaging Spectrograph on
  the 3.5-m ARC telescope at Apache Point Observatory. The spectrum
  shows prominent H-alpha emission with a P-Cyg profile. The minimum
  of the H-alpha absorption is at 642.5 nm. Using the redshift z =
  0.015627 for UGC 12137 (from Wegner et al. 1993, A.J. 105, 1251;
  via NED), this corresponds to a velocity of 11000 km/s. Running the
  SNID software, the spectrum resembles SN 2004et at fifteen days after
  maximum, indicating that 2013do is a type-II-P supernova.

Title: Supernova 2013dq in UGC 525 = Psn J00513484+2943149
Authors: Howerton, S.; Drake, A. J.; Djorgovski, S. G.; Mahabal, A.;
   Graham, M. J.; Williams, R.; Prieto, J. L.; Catelan, M.; Christensen,
   E.; Larson, S. M.; Rachubo, A. A.; Leonard, D. C.; Follette, K.;
   Sheehan, P.; Bailey, V.; McCarthy, D.; Moustakas, J.; Barrows, J.;
   Bosset, E.; Buckley, E.; Burd, D.; Calahan, J.; Ceesay, I.; Douglas,
   E.; Feeney, C.; Fornari, T.; Fox, A.; Fishwick, H.; Gano, H.; Green,
   C.; Griggs, J.; Hart, K.; Hart, S.; Hartman, K.; Holt, A.; Hooper,
   E.; Hume, S.; Jaeggli, S.; Lesser, D.; Kerr, M.; Kopans-Johnson, C.;
   Kumar, K.; Lackey, A.; Laube, S.; Marshall, E.; Martinez, M.; Mehta,
   G.; Melbourne, K.; Meshel, M.; Myers, C.; Puranen, E.; Schlingman,
   A.; Shen, K.; Stock, N.; Stillman, C.; Tinker, J.; Whitesell, B.
Bibcode: 2013CBET.3573....1H
Altcode: 2013CBET.3573A...1H
  S. Howerton, Arkansas City, KS, U.S.A.; A. J. Drake, S. G. Djorgovski,
  A. Mahabal, M. J. Graham, and R. Williams, California Institute
  of Technology; J. L. Prieto, Princeton University; M. Catelan,
  Pontificia Universidad Catolica de Chile; and E. Christensen and
  S. M. Larson, Lunar and Planetary Laboratory, University of Arizona,
  report the Catalina Real-time Transient Survey discovery of an
  apparent supernova in public images from the Catalina Sky Survey
  (CSS). SN 2013 UT R.A. (2000.0) Decl. Mag. Offset 2013dq June 27.44 0
  51 34.84 +29 43 14.9 16.8 4".3 E, 15".6 N The variable was designated
  PSN J00513484+2943149 when it was posted at the Central Bureau's TOCP
  webpage and is here designated SN 2013dq based on the spectroscopic
  confirmation reported below. Additional CCD magnitudes for 2013dq:
  Feb. 8.14 UT, [19.5 (CSS); June 28.814, 17.2 (Joseph Brimacombe,
  Cairns, Australia; 41-cm telescope + infrared filter; bandpass &gt;
  700 nm; position end figures 35s.02, 13".8; image posted at website URL
  http://www.flickr.com/photos/43846774@N02/9174594184/). A. A. Rachubo
  and D. C. Leonard, San Diego State University; K. Follette, P. Sheehan,
  V. Bailey, and D. McCarthy, University of Arizona; J. Moustakas,
  Siena College; J. Barrows, E. Bosset, E. Buckley, D. Burd, J. Calahan,
  I. Ceesay, E. Douglas, C. Feeney, T. Fornari, A. Fox, H. Fishwick,
  H. Gano, C. Green, J. Griggs, K. Hart, S. Hart, K. Hartman, A. Holt,
  E. Hooper, S. Hume, S. Jaeggli, D. Lesser, M. Kerr, C. Kopans-Johnson,
  K. Kumar, A. Lackey, S. Laube, E. Marshall, M. Martinez, G. Mehta,
  K. Melbourne, M. Meshel, C. Myers, E. Puranen, A. Schlingman,
  W. Schlingman, W. M. Schlingman, K. Shen, N. Stock, C. Stillman,
  J. Tinker, and B. Whitesell, 2013 Advanced Teen Astronomy Camp, report
  that inspection of a low-dispersion optical spectrogram (range 370-680
  nm) of PSN J00513484+2943149 = SN 2013dq, obtained in heavy twilight
  with the 2.3-m Bok telescope (+ Boller &amp; Chivens spectrograph)
  at Steward Observatory on June 28 UT, shows it to be an aging type-Ia
  supernova. After correcting for a redshift of 4931 km/s for the assumed
  host galaxy, UGC 525 (Falco et al. 1999, PASP 111, 438; via NED),
  reasonable matches are found with normal type-Ia supernovae at epochs
  ranging between 40 and 65 days after maximum light, although there
  is a notable absence of emission in 2013dq near 500.0 nm (attributed
  to Fe II; Branch et al. 2008, PASP 120, 135) that is usually seen
  at this phase. The most convincing individual spectral match is made
  with SN 1999gp at 50 days post-maximum (Matheson et al. 2008, A.J. 135,
  1598), which exhibited a broad, 1991T-like light-curve (dm15[B] = 0.80;
  Hicken et al. 2009, Ap.J. 700, 331), a "shallow silicon" maximum-light
  spectrum (Jha et al. 2000, IAUC 7341; Branch et al. 2009, PASP 121,
  238), and somewhat-muted 500.0-nm emission at this phase.

Title: 1565 nm Observations of the transit of Venus, Proxy for a
    Transiting Exoplanet
Authors: Jaeggli, Sarah A.; Reardon, K. P.; Pasachoff, J. M.;
   Schneider, G.; Widemann, T.; Tanga, P.
Bibcode: 2013SPD....44..150J
Altcode:
  The transit of Venus in June 2012 provided a unique chance to view its
  atmosphere as we might see that of a transiting Cytherean exoplanet,
  through scattered and refracted illumination from its parent star. We
  performed spectroscopy and polarimetry during the transit of Venus
  focusing on extracting signatures of CO2 absorption of Venus from the
  solar spectrum. Although the predicted CO2 transmission spectrum of
  Venus was not particularly strong at 1565 nm, this region of the H-band
  often used in magnetic-field studies of the Sun's photosphere provides
  a particularly flat solar continuum with few atmospheric and molecular
  lines. Observations of Venus were taken throughout first contact
  and on the solar disk using the Facility InfraRed Spectropolarimeter
  on the Dunn Solar Telescope at the National Solar Observatory. The
  transit also provided a unique opportunity to investigate instrumental
  effects. In this poster we discuss initial results from the transit,
  including estimates for an exoplanet detection of this kind, preliminary
  comparison with atmospheric models, and the stray light properties
  of the instrument. This work was performed in collaboration with the
  Williams College Venus transit expedition, which was sponsored by Natl
  Geog/Comm for Research and Exploration.

Title: National Student Solar Spectrograph Competition Overview
    and Results
Authors: Des Jardins, Angela C.; Larimer, R.; Shaw, J. A.; Kankelborg,
   C.; Palmer, C.; Key, J. S.; Nakagawa, W.; Springer, L.; Knighton,
   W.; Repasky, K. S.; Pust, N. J.; Babbitt, W.; Jaeggli, S. A.; Hobish,
   M. K.; Wilson, E. W.; Anderson, M.; Boger, J.; McCrady, N.; Naylor,
   J.; Turcotte, S.; Lines, T.; Strobel, N.; Cooper, W.; Darke, R.; Head,
   R.; Kimball, D.; Kissel, G.; Buck, K.; Lawrence, L.; Wragg, J.; Runyon,
   C. J.; Spacher, P.; Dumitriu, I.; Nollenberg, J. G.; Estaban, R.
Bibcode: 2013SPD....44..160D
Altcode:
  The yearly National Student Solar Spectrograph Competition (NSSSC)
  is Montana Space Grant Consortium's Education and Public Outreach
  (EP/O) Program for NASA's Interface Region Imaging Spectrograph (IRIS)
  mission. The NSSSC is designed to give institutions with less aerospace
  activity such as Minority Serving Institutions and Community Colleges
  an opportunity for hands on real world research experience. The NSSSC
  provides students from across the country the opportunity to work as
  part of an undergraduate interdisciplinary team to design, build and
  test a ground based solar spectrograph. Over the course of nine months,
  teams come up with their own science goals and then build an instrument
  to collect data in support of their goals. Teams then travel to Bozeman,
  MT to demonstrate their instruments and present their results in a
  competitive science fair environment. This poster will present the
  2012-2013 competition results.Abstract (2,250 Maximum Characters):
  The yearly National Student Solar Spectrograph Competition (NSSSC)
  is Montana Space Grant Consortium's Education and Public Outreach
  (EP/O) Program for NASA's Interface Region Imaging Spectrograph (IRIS)
  mission. The NSSSC is designed to give institutions with less aerospace
  activity such as Minority Serving Institutions and Community Colleges
  an opportunity for hands on real world research experience. The NSSSC
  provides students from across the country the opportunity to work as
  part of an undergraduate interdisciplinary team to design, build and
  test a ground based solar spectrograph. Over the course of nine months,
  teams come up with their own science goals and then build an instrument
  to collect data in support of their goals. Teams then travel to Bozeman,
  MT to demonstrate their instruments and present their results in a
  competitive science fair environment. This poster will present the
  2012-2013 competition results.

Title: Spectroscopy of PSN J00513484+2943149 in UGC 525
Authors: Rachubo, A. A.; Leonard, D. C.; Follette, K.; Sheehan, P.;
   Bailey, V.; McCarthy, D.; Moustakas, J.; Barrows, J.; Bosset, E.;
   Buckley, E.; Burd, D.; Calahan, J.; Ceesay, I.; Douglas, E.; Feeney,
   C.; Fornari, T.; Fox, A.; Fishwick, H.; Gano, H.; Green, C.; Griggs,
   J.; Hart, K.; Hart, S.; Hartman, K.; Holt, A.; Hooper, E.; Hume,
   S.; Jaeggli, S.; Lesser, D.; Kerr, M.; Kopans-Johnson, C.; Kumar,
   K.; Lackey, A.; Laube, S.; Marshall, E.; Martinez, M.; Mehta, G.;
   Melbourne, K.; Meshel, M.; Myers, C.; Puranen, E.; Schlingman, A.;
   Schlingman, W.; Schlingman, W. M.; Shen, K.; Stock, N.; Stillman,
   C.; Tinker, J.; Whitesell, B.
Bibcode: 2013ATel.5176....1R
Altcode:
  We report that inspection of a low-dispersion optical spectrum
  (range 370-680 nm) of PSN J00513484+2943149 (CBAT TOCP), obtained in
  heavy twilight with the 2.3-m Bok telescope (+ Boller &amp; Chivens
  spectrograph) at Steward Observatory on June 28 UT, shows it to be an
  aging type-Ia supernova. After correcting for a redshift of 4931 km/s
  for the assumed host galaxy, UGC 525 (Falco et al. 1999, PASP, 111,
  438; via NED), reasonable matches are found with normal SNe Ia at
  epochs ranging between 40 and 65 days after maximum light, although
  there is a notable absence of emission in PSN J00513484+2943149 near
  5000 Angstrom (attributed to Fe II; Branch et al.

Title: Transit Observations of Venus's Atmosphere in 2012 from
    Terrestrial and Space Telescopes as Exoplanet Analogs
Authors: Pasachoff, Jay M.; Schneider, G.; Babcock, B. A.; Lu, M.;
   Penn, M. J.; Jaeggli, S. A.; Galayda, E.; Reardon, K. P.; Widemann,
   T.; Tanga, P.; Ehrenreich, D.; Vidal-Madjar, A.; Nicholson, P. D.;
   Dantowitz, R.
Bibcode: 2013AAS...22221701P
Altcode:
  We extensively observed the 8 June 2012 transit of Venus from several
  sites on Earth; we provide this interim status report about this and
  about two subsequent ToVs observed from space. From Haleakala Obs., we
  observed the entire June transit over almost 7 h with a coronagraph of
  the Venus Twilight Experiment B filter) and with a RED Epic camera to
  compare with simultaneous data from ESA's Venus Express, to study the
  Cytherean mesosphere; from Kitt Peak, we have near-IR spectropolarimetry
  at 1.6 µm from the aureole and during the disk crossing that compare
  well with carbon dioxide spectral models; from Sac Peak/IBIS we have
  high-resolution imaging of the Cytherean aureole for 22 min, starting
  even before 1st contact; from Big Bear, we have high-resolution imaging
  of Venus's atmosphere and the black-drop effect through 2nd contact;
  and we had 8 other coronagraphs around the world. For the Sept 21 ToV
  as seen from Jupiter, we had 14 orbits of HST to use Jupiter's clouds
  as a reflecting surface to search for an 0.01% diminution in light and a
  differential drop that would result from Venus's atmosphere by observing
  in both IR/UV, for which we have 170 HST exposures. As of this writing,
  preliminary data reduction indicates that variations in Jovian clouds
  and the two periods of Jupiter's rotation will be too great to allow
  extraction of the transit signal. For the December 20 ToV as seen from
  Saturn, we had 22 hours of observing time with VIMS on Cassini, for
  which we are looking for a signal of the 10-hr transit in total solar
  irradiance and of Venus's atmosphere in IR as an exoplanet-transit
  analog. Our Maui &amp; Sac Peak expedition was sponsored by National
  Geographic Society's Committee for Research and Exploration; HST data
  reduction by NASA: HST-GO-13067. Some of the funds for the carbon
  dioxide filter for Sac Peak provided by NASA through AAS's Small
  Research Grant Program. We thank Rob Ratkowski of Haleakala Amateur
  Astronomers; Rob Lucas, Aram Friedman, Eric Pilger, Stan Truitt,
  and Steve Bisque/Software Bisque for Haleakala support/operations;
  Vasyl Yurchyshyn and Joseph Gangestad '06 of The Aerospace Corp. at
  Big Bear Solar Obs; LMSAL and Hinode science/operations team.

Title: Multi-height Spectropolarimetry Of Sunspots With Firs And Ibis
Authors: Jaeggli, Sarah A.; Lin, H.; Tritschler, A.
Bibcode: 2012AAS...22020606J
Altcode:
  The effects of radiative transfer prevent the characterization of
  the magnetic field at a single geometric height in the photosphere
  of a sunspot. Therefore, a full 3D characterization of the magnetic
  field is necessary to understand many properties of sunspots, such as
  the true state of hydrostatic equilibrium. Many current and proposed
  solar spectropolarimeters are capable of taking near-simultaneous
  observations at multiple wavelengths. Combining these rich datasets
  provides a welcome problem to the community. We present the first joint
  observations of the magnetically sensitive photospheric Fe I lines at
  630 and 1565 nm taken with the Facility Infrared Spectropolarimeter
  (FIRS); and the chromospheric Ca II line at 854 nm taken with the
  Interferometric Bi-Dimensional Spectrometer (IBIS); both instruments
  operated at the Dunn Solar Telescope. These wavelengths allow us to
  probe the magnetic field over a broad range of heights, from the
  bottom of the photosphere to the chromosphere. We investigate the
  magnetic field topologies of several sunspots of different size and
  magnetic complexity.

Title: Comparison of Multi-Height Observations with a 3D MHD
    Sunspot Model
Authors: Jaeggli, S. A.; Lin, H.; Uitenbroek, H.; Rempel, M.
Bibcode: 2012ASPC..456...67J
Altcode:
  In sunspots the contribution to the horizontal pressure support from the
  curvature force and the geometrical height of formation which magnetic
  field measurements sample are poorly constrained observationally due to
  the effect of radiative transfer. In cool atmospheres, observations of
  the sunspot photosphere probe geometrically deeper layers, information
  on the magnetic field gradients cannot be easily derived even using
  multi-wavelength, multi-height observations. Recent MHD atmosphere
  models of sunspots analyzed with the Rybiki-Hummer radiative transfer
  code allow for direct comparison with simultaneous multi-height
  observations of the Fe I magnetic field diagnostics at 1565 and 630.2
  nm in sunspots observed using the Facility Infrared Spectropolarimeter
  at the Dunn Solar Telescope.

Title: Spies - Spectral Polarimetric Imager For The Energetic Sun
Authors: Lin, Haosheng; Jaeggli, S.
Bibcode: 2012AAS...22012306L
Altcode:
  Spectropolarimetric observation with uncompromised spatial, spectral,
  and temporal resolution simulatneously over a substantial 2D field and
  multiple spectral lines is the key to the resolution of many important
  questions in modern solar physics. While 2D imaging spectroscopy
  based on fiber optics integral field unit and image slicer has a long
  history nighttime astronomy, adaptation for solar observation occured
  only recently. This paper will present preliminary results of magnetic
  field observation in the HeI 1083 nm and FeI 1565 nm lines obtained
  with SPIES --- a true imaging spectropolarimeter based on a large format
  (64 x 32 fibers input array) fiber-optic array optimized for the study
  of evolution of magnetic and thermodynamic properties of energetic and
  dynamic phenomena of the sun. We will also discuss considerations for
  the use of fiber-optic array for solar spectropolarimetric applications,
  as well as the design of SPIES.

Title: Non-Stationary Deconvolution for the IRIS NUV Slit-Jaw Imager
Authors: Jaeggli, Sarah A.; Kankelborg, Charles C.; IRIS Team
Bibcode: 2012decs.confE..49J
Altcode:
  High spatial resolution context imaging is essential to linking spatial
  structures with spectral signatures in the chromosphere, a critical
  part of the science requirements for IRIS (Interface Region Imaging
  Spectrograph). Measurements of the optical figure of the Solc filter
  indicate that the NUV slit-jaw imager on IRIS will have a somewhat
  broader PSF than the other instrument channels. We have developed an
  advanced deconvolution technique which combines measured PSFs sampled
  over the image plane to achieve the best correction for each pixel. We
  have conducted an analysis of this technique on synthetic data, and
  we assess the quality of the resulting images containing a variety of
  simulated effects, including cosmic ray hits, photon counting noise,
  discrete energetic solar events (flares), and saturation and overflow
  artifacts.

Title: On Molecular Hydrogen Formation and the Magnetohydrostatic
    Equilibrium of Sunspots
Authors: Jaeggli, S. A.; Lin, H.; Uitenbroek, H.
Bibcode: 2012ApJ...745..133J
Altcode: 2011arXiv1110.0575J
  We have investigated the problem of sunspot magnetohydrostatic
  equilibrium with comprehensive IR sunspot magnetic field survey
  observations of the highly sensitive Fe I lines at 15650 Å and nearby
  OH lines. We have found that some sunspots show isothermal increases
  in umbral magnetic field strength which cannot be explained by the
  simplified sunspot model with a single-component ideal gas atmosphere
  assumed in previous investigations. Large sunspots universally
  display nonlinear increases in magnetic pressure over temperature,
  while small sunspots and pores display linear behavior. The formation
  of molecules provides a mechanism for isothermal concentration of
  the umbral magnetic field, and we propose that this may explain the
  observed rapid increase in umbral magnetic field strength relative to
  temperature. Existing multi-component sunspot atmospheric models predict
  that a significant amount of molecular hydrogen (H<SUB>2</SUB>) exists
  in the sunspot umbra. The formation of H<SUB>2</SUB> can significantly
  alter the thermodynamic properties of the sunspot atmosphere and
  may play a significant role in sunspot evolution. In addition to the
  survey observations, we have performed detailed chemical equilibrium
  calculations with full consideration of radiative transfer effects
  to establish OH as a proxy for H<SUB>2</SUB>, and demonstrate that a
  significant population of H<SUB>2</SUB> exists in the coolest regions
  of large sunspots.

Title: An Observational Study of the Formation and Evolution of
    Sunspots
Authors: Jaeggli, Sarah A.; Lin, H.; Uitenbroek, H.
Bibcode: 2011SPD....42.0302J
Altcode: 2011BAAS..43S.0302J
  It is well known that the thermal-magnetic relation in sunspots can
  be non-linear. Previous investigations ascribe the non-linearity
  of the relation to changing geometrical height of the measurement
  due to radiative transfer effects (Wilson Depression) and the poorly
  determined magnetic field curvature force. However, the very coolest
  regions of some sunspots show a rapid increase in umbral magnetic
  field strength relative to temperature which cannot be explained
  by the simplified sunspot model with single-component ideal gas
  atmosphere which has been previously assumed. This represents a
  fundamental flaw in our understanding of the sunspot equilibrium
  problem. Existing multiple-component sunspot atmospheric models
  predict that a large amount of molecular hydrogen (H2) exists in
  the sunspot umbra. The formation of molecules provides a mechanism
  for isothermal concentration of the umbral magnetic field which may
  explain the observed rapid increase in umbral magnetic field strength
  relative to temperature. We have characterized the equilibrium forces
  in sunspots using simultaneous visible and IR sunspot magnetic field
  survey observations of the highly sensitive Fe I lines at 6302 and
  15650 Angstroms and nearby OH lines which have been conducted with
  the new Facility Infrared Spectropolarimeter (FIRS) at the Dunn Solar
  Telescope. We have performed detailed chemical equilibrium calculations
  with full consideration of radiative transfer effects to establish OH
  as a proxy for H2, and demonstrate that a significant population of H2
  exists in the coolest regions of large and more mature sunspots. We
  further point out that the formation of H2 can significantly alter
  the thermodynamic properties of the sunspot atmosphere and may play
  a significant role in sunspot evolution.

Title: Spectropolarimetry of Chromospheric Magnetic and Velocity
    Structure Above Active Regions
Authors: Schad, T. A.; Jaeggli, S. A.; Lin, H.; Penn, M. J.
Bibcode: 2011ASPC..437..483S
Altcode: 2011arXiv1101.0631S
  Active regions often host large-scale gas flows in the
  chromosphere presumably directed along curved magnetic field
  lines. Spectropolarimetric observations of these flows are critical to
  understanding the nature and evolution of their anchoring magnetic
  structure. We discuss recent work with the Facility Infrared
  Spectropolarimeter (FIRS) located at the Dunn Solar Telescope in New
  Mexico to achieve high-resolution imaging-spectropolarimetry of the Fe
  I lines at 630 nm, the Si I line at 1082.7 nm, and the He I triplet at
  1083 nm. We present maps of the photospheric and chromospheric magnetic
  field vector above a sunspot as well as discuss characteristics of
  surrounding chromospheric flow structures.

Title: Molecule Formation and Magnetic Field Evolution in Sunspots
Authors: Jaeggli, S. A.; Lin, H.; Uitenbroek, H.
Bibcode: 2011ASPC..437..473J
Altcode:
  In a sunspot the magnetic field provides horizontal support to keep
  the warm, high pressure photosphere from intruding into the cool,
  low pressure sunspot atmosphere. In the very coolest regions of
  the umbra a rapid increase in magnetic field strength relative to
  temperature has been observed by many authors although its origins
  have remained unknown. In these regions the magnetic and gas pressure
  forces have found a different state which the current simplified theory
  of magnetohydrostatic equilibrium cannot quantitatively describe. It
  is well known that molecules form in sunspots. The formation of a
  large molecular fraction would alter the physical characteristic of
  the gas, providing a mechanism for concentrating the umbral magnetic
  field. The formation of molecules may be responsible for the observed
  rapid increase of the magnetic field strength observed in the coolest
  regions of the sunspots and may play a significant role in sunspot
  evolution. We investigate this problem with atmospheric models and
  present preliminary results from observations taken with the new
  Facility Infrared Spectropolarimeter on the Dunn Solar Telescope.

Title: An observational study of the formation and evolution of
    sunspots
Authors: Jaeggli, Sarah A.
Bibcode: 2011PhDT........97J
Altcode:
  This dissertation focuses on the problem of molecules and the
  horizontal balance of forces in sunspots. Sunspots are quasi-static
  features on the solar surface and can be considered to be in a
  state of equilibrium. The weaker gas pressure of the cool sunspot
  interior is horizontally supported against the higher pressure of
  the hotter quiet-Sun by a strong vertical magnetic field. However,
  some sunspots show a rapid increase in magnetic pressure relative to
  the temperature of the gas in the coolest regions of the sunspot,
  implying that an isothermal decrease in the gas pressure must have
  occurred. The current model of sunspots is unable to describe this
  deviation from the assumed equilibrium state of the magnetic field
  and thermal gas pressure observed in these sunspots. Another method
  of altering the pressure of the gas must be occurring. The formation
  of molecules in sunspots may be the key to solving this puzzle. The
  sunspot interior provides a cool environment where molecules can form
  in abundance. As atoms become bound into molecules the total particle
  number of the gas is decreased. A sufficiently large molecular fraction
  could significantly alter the properties of the sunspot plasma,
  and specifically provide a mechanism for concentrating the magnetic
  field by non-thermally lowering the gas pressure. I have investigated
  the equilibrium condition of sunspots of different sizes and in a
  variety of evolutionary phases through a Milne-Eddington inversion
  of spectropolarimetric observations of the Zeeman-split Fe I lines
  at 6302 and 15650 A to obtain their thermal and magnetic topology. I
  carried out a calculation of the detailed radiative transfer and
  chemical equilibrium of model sunspot atmospheres to determine the
  molecular gas fraction. Several sunspots show unambiguous cases of
  isothermal magnetic field intensification, which can only be explained
  by the formation or destruction of a large molecular population. All
  sunspots with magnetic fields stronger than 2500 G and temperatures
  cooler than 5800 K consistently show a signature of magnetic field
  over-concentration, consistent with molecular hydrogen formation of
  a few percent of the total gas fraction. The formation of this large
  molecular population has widespread implications for sunspot physics.

Title: Magnetic Field Measurements at the Photosphere and Coronal Base
Authors: Judge, P. G.; Centeno, R.; Tritschler, A.; Uitenbroek, H.;
   Jaeggli, S.; Lin, H.
Bibcode: 2010AGUFMSH31A1783J
Altcode:
  We have obtained vector polarimetric measurements in lines of Fe I
  (630nm), Ca II (854nm) and He I (1083nm) of several active regions
  during 3-14 June 2010. The measurements were made at the Dunn Solar
  Telescope at Sacramento Peak Observatory, using the FIRS and IBIS
  instruments simultaneously. We discuss these and SDO data for NOAA
  11076. The seeing was very good or excellent and the adaptive
  optics system functioned well. In this preliminary analysis we
  compare extrapolations of photospheric fields with the constraints
  available from Stokes polarimetry, including the morphology and
  kinematic properties of fibrils. Connections to the corona will also be
  discussed. The implications for field extrapolations from photospheric
  measurements will be discussed. We will make the reduced data freely
  available on the web for interested researchers.

Title: Utilization of redundant polarized solar spectra to infer
    the polarization properties of the new generation of large aperture
    solar telescopes
Authors: Elmore, David F.; Lin, Haosheng; Socas Navarro, Héctor;
   Jaeggli, Sarah A.
Bibcode: 2010SPIE.7735E..4EE
Altcode: 2010SPIE.7735E.147E
  Spectro-polarimetry plays an important role in the study of solar
  magnetism and strongly influences the design of the new generation of
  solar telescopes. Calibration of the polarization properties of the
  telescope is a critical requirement needed to use these observations to
  infer solar magnetic fields. However, the large apertures of these new
  telescopes make direct calibration with polarization calibration optics
  placed before all the telescope optical elements impractical. It is
  therefore desirable to be able to infer the polarization properties
  of the telescope optical elements utilizing solar observations
  themselves. Taking advantage of the fact that the un-polarized,
  linearly, and circularly polarized spectra originating from the Sun are
  uncorrelated, we have developed techniques to utilize observations
  of solar spectra with redundant combination of the polarization
  states measured at several different telescope configurations to
  infer the polarization properties of the telescope as a whole and of
  its optical elements. We show results of these techniques applied to
  spectro-plarimetric data obtained at the Dunn Solar Telescope.

Title: Magnetic field measurements at the photosphere and coronal base
Authors: Judge, Philip; Centeno, R.; Tritschler, A.; Uitenbroek, H.;
   Jaeggli, S.; Lin, H.
Bibcode: 2010shin.confE..56J
Altcode:
  We have obtained vector polarimetric measurements in lines of Fe I
  (630nm), Ca II (854nm) and He I (1083) of several active regions during
  3-14 June 2010. The measurements were made at the Dunn Solar Telescope
  at Sacramento Peak Observatory, using the FIRS and IBIS instruments
  simultaneously. We discuss data for NOAA 11076 observed on 4 June
  2010. The seeing was very good or excellent and the adaptive optics
  system functioned well. In this preliminary analysis we compare linear
  extrapolations of photospheric fields with the constraints available
  from Stokes polarimetry, including the morphology and kinematic
  properties of fibrils. The implications for field extrapolations from
  photospheric measurements will be discussed. We will make the reduced
  data freely available on the web for interested researchers.

Title: FIRS: a new instrument for photospheric and chromospheric
    studies at the DST.
Authors: Jaeggli, S. A.; Lin, H.; Mickey, D. L.; Kuhn, J. R.; Hegwer,
   S. L.; Rimmele, T. R.; Penn, M. J.
Bibcode: 2010MmSAI..81..763J
Altcode:
  The simultaneous observation of select spectral lines at optical and
  infrared wavelengths allows for the determination of the magnetic
  field at several photospheric and chromospheric heights and thus
  the 3D magnetic field gradient in the solar atmosphere. The Facility
  Infrared Spectropolarimeter (FIRS) is a newly completed, multi-slit,
  dual-beam spectropolarimeter installed at the Dunn Solar Telescope
  (DST) at Sacramento Peak (NSO/SP). Separate optics and polarimeters
  simultaneously observe two band-passes at visible and infrared
  wavelengths with a choice of two modes: the Fe I 6302 Å and 15648 Å
  lines in the photosphere; or the Fe I 6302 Å and He I 10830 Å line
  in the photosphere and high chromosphere, respectively. FIRS can also
  operate simultaneously with a white light camera, G-band imager, and
  the Interferometric Bi-dimensional Spectrometer (IBIS) observing the
  mid-chromospheric Ca II 8542 Å line. The instrument uses four parallel
  slits to sample four slices of the solar surface simultaneously to
  achieve fast, diffraction-limited precision imaging spectropolarimetry,
  enabling the study of MHD phenomena with short dynamic time scales.

Title: The Facility IR Spectropolarimeter for the Dunn Solar Telescope
Authors: Jaeggli, S. A.; Lin, H.; Mickey, D. L.; Kuhn, J. R.; Hegwer,
   S. L.; Rimmele, T. R.; Penn, M. J.
Bibcode: 2008AGUSMSH31A..11J
Altcode:
  The Facility IR Spectropolarimeter(FIRS) is a multi-slit
  spectropolarimeter designed for the Dunn Solar Telescope (DST) at the
  National Solar Observatory on Sacramento Peak (NSO/SP) in New Mexico to
  study magnetism on the solar surface. The instrument samples adjacent
  slices of the solar surface using four parallel slits to achieve high
  cadence, diffraction-limited, precision imaging-spectropolarimetry. Due
  to the versatile, multi-armed design of the spectrograph, up to
  four spectral lines at visible and infrared wavelengths, covering
  four different heights in the solar atmosphere, can be observed
  simultaneously. In this poster-paper we will describe the design,
  capabilities, and performance of the instrument.

Title: Erratum: ``Localized Enhancements of Fe<SUP>+10</SUP> Density
    in the Corona as Observed in Fe XI 789.2 nm during the 2006 March
    29 Total Solar Eclipse'' (<A href="/abs/2007ApJ...663..598H">ApJ,
    663, 598 [2007]</A>)
Authors: Habbal, Shadia Rifai; Morgan, Huw; Johnson, Judd; Arndt,
   Martina Belz; Daw, Adrian; Jaeggli, Sarah; Kuhn, Jeff; Mickey, Don
Bibcode: 2007ApJ...670.1521H
Altcode:
  The eclipse image of Figure 3 was provided to the authors by
  Jackob Strikis of the Elizabeth Observatory, Athens, who claimed
  authorship. However, shortly after publication the authors discovered
  that this eclipse image was in fact a preliminary version of an
  image belonging to Prof. Miloslav Druckmüller, taken during the
  2006 total solar eclipse from Libya at 30°56.946' N, 24°14.301'
  E, and at an altitude of 158 m. This image can be found at <A
  href="/abs/2007ApJ...663..598H">ApJ, 663, 598 [2007]</A>. We extend our
  gratitude to Prof. Druckmüller, from Brno University of Technology,
  Czech Republic, who brought this incident to our attention, and who
  has graciously accepted our apology for this unintentional mishap. A
  forthcoming article in collaboration with Prof. Druckmüller is in
  preparation.

Title: Detection of an Extended Near-Sun Neutral Helium Cloud from
    Ground-based Infrared Coronagraph Spectropolarimetry
Authors: Kuhn, J. R.; Arnaud, J.; Jaeggli, S.; Lin, H.; Moise, E.
Bibcode: 2007ApJ...667L.203K
Altcode:
  Sensitive spectropolarimetric observations from the Haleakala SOLARC
  coronagraph and infrared imaging spectropolarimeter have detected an
  extended diffuse surface brightness flux at the 1083 nm wavelength
  of neutral helium (He I). This has the polarization signature of
  light scattered by an extended He I cloud in the vicinity of the
  Sun. The He I scattered surface brightness appears to be consistent
  with a previous eclipse measurement and satellite observations of the
  local interstellar medium (LISM) helium wind (LISW), obtained using
  observations of the He I UV resonance line at 58.4 nm. The sensitivity
  of the infrared coronagraphic method suggests that the LISW interaction
  with the local solar wind can have observable consequences that may
  yield a useful ground-based technique for studying the coronal and
  interplanetary plasma.

Title: Localized Enhancements of Fe<SUP>+10</SUP> Density in the
    Corona as Observed in Fe XI 789.2 nm during the 2006 March 29 Total
    Solar Eclipse
Authors: Habbal, Shadia Rifai; Morgan, Huw; Johnson, Judd; Arndt,
   Martina Belz; Daw, Adrian; Jaeggli, Sarah; Kuhn, Jeff; Mickey, Don
Bibcode: 2007ApJ...663..598H
Altcode:
  The first ever image of the full solar corona in the Fe XI 789.2 nm
  spectral line was acquired during the total solar eclipse of 2006
  March 29. Several striking features stand out in the processed image:
  (1) The emission extended out to at least 3 R<SUB>solar</SUB> in
  streamers. (2) A bubble-like structure, occupying a cone of about 45°
  and reaching out to 1 R<SUB>solar</SUB> above the limb, was observed
  southward of a bright active region complex close to the limb. (3)
  Localized intensity enhancements were found in different parts of
  the corona at heights ranging from 1.2 to 1.5 R<SUB>solar</SUB>. (4)
  Striations extended out to the edge of the field of view above an almost
  north-south-oriented prominence. Comparison with the corresponding
  white-light image taken simultaneously during the eclipse showed
  no evidence for these localized enhancements, and the bubble-like
  structure and striations, while present, did not stand out in the same
  manner. The extent of the Fe XI emission is attributed to the dominance
  of radiative over collisional excitation in the formation of that
  spectral line. The localized intensity enhancements, observed only in
  Fe XI and not in white light, are a signature of localized increases
  in Fe<SUP>+10</SUP> density relative to electron density. These are
  the first observations to show direct evidence of localized heavy
  ion density enhancements in the extended corona. They point to the
  importance of implementing observations of the Fe XI 789.2 nm line with
  existing or future coronagraphs for the exploration of the physical
  processes controlling the behavior of heavy ions in different source
  regions of the solar wind.

Title: The Starburst-AGN Connection: Integral Field Spectroscopy of
    Merging and Seyfert 2 Galaxies
Authors: Jaeggli, Sarah A.; Joseph, R. D.
Bibcode: 2007AAS...210.1207J
Altcode: 2007BAAS...39..109J
  Luminous galaxies can be powered by two different mechanisms, accretion
  of matter onto a super-massive black hole at the nucleus, and a rapid
  burst of star formation that produces many luminous young stars, a
  "starburst." Both events occur inside a large optical depth of dust:
  a Seyfert 2 through its dusty torus and starbursts through their dusty
  cocoons. Using the UIST integral field unit on the United Kingdom
  Infrared Telescope we make observations in the K-band where obscuration
  due to dust is ten times less than at visible wavelengths. With
  a resolution of 900 and a field of 6 x 3.3 square arcseconds, the
  integral field unit allows us to use infrared spectral diagnostics
  for a sample of galaxies identified as merging starbursts and another
  sample identified as Seyfert 2s to investigate the presence of both
  starbursts and AGNs in both samples, and look for evidence of the
  starburst-AGN connection.

Title: Broadband Spectroscopy of the Corona during the Total Solar
    Eclipse of March 29, 2006
Authors: Jaeggli, Sarah A.; Habbal, S. R.; Kuhn, J. R.; Nayfeh, M. H.
Bibcode: 2006AAS...209.1601J
Altcode: 2006BAAS...38..918J
  We present coronal observations from the total solar eclipse of 29
  March 2006 taken near Waw al Namus, Libya. During the 4 minutes and 6
  seconds of totality, observations were made with a tracking collecting
  mirror and fiber-fed spectrograph. The spectrograph used is a high
  quantum efficiency commercial Ocean Optics QE65000 Spectrometer with a
  wavelength range of 350 to 1100 nm, and spectral resolution of about
  0.75 nm. High quantum efficiency allowed for many short exposures
  of the inner (100 msec) and outer (10,000 msec) corona during the
  eclipse. Important spectral features, and the difference in color
  between the inner and outer corona are identified. Atmospheric
  contributions are discussed. Likely candidates for the nature of
  dust grains contributing to the F-corona measurements are also
  presented. These are compared with laboratory spectra of silicon
  nanoparticles.

Title: Polarimetric Imaging and Spectroscopy of the Corona from 400
    to 2000 nm during the Total Solar Eclipse of 29 March 2006
Authors: Habbal, S. R.; Kuhn, J.; Mickey, D.; Morgan, H.; Jaeggli,
   S.; Johnson, J.; Daw, A.; Arndt, M. B.; Nayfeh, M.; Roussev, I.
Bibcode: 2006AGUFMSH44A..06H
Altcode:
  Total solar eclipses continue to offer unique opportunities for
  exploring the solar corona, in particular for validating new concepts,
  and testing new instrumentation. We report on the results of the
  observations taken during the total solar eclipse of 29 March 2006. The
  eclipse was observed from Waw AnNamous, Libya, under perfect seeing
  conditions. A complement of imaging and spectroscopic polarization
  measurements, covering the wavelength range from 400 to 2000 nm, were
  used. Among the highlights of the observations were the unexpected
  radial extent of the emission from the Fe XI 789.2 nm spectral line,
  which has proven to have significant potential for future coronagraphic
  measurements, and the appearance of presently unidentified spectral
  lines in the visible and near infrared part of the spectrum. The
  implications of these results for the coronal magnetic field, and the
  near-Sun dust environment will be discussed.

Title: Penumbral Moving Magnetic Features
Authors: Penn, M. J.; Jaeggli, S. A.; Henney, C. J.; Luszcz, S.;
   Walton, S. R.
Bibcode: 2006ASPC..358...31P
Altcode:
  Moving magnetic features are observed in the penumbrae of two sunspots
  with time sequences of vector magnetic field measurements taken in
  the infrared Fe I 1565 nm spectral line (g=3). These features move
  with similar radial velocities as previously observed continuum and
  G-band features, and confirm a short sequence of penumbral magnetic
  observations in the visible. These features move with similar speeds
  to the moving magnetic features seen outside sunspot penumbrae, and
  in some cases they are seen to cross the penumbral boundary and move
  across the sunspot moat. Magnetic and flow parameters are briefly
  compared with predictions from the moving flux tube model.

Title: Using Polarimetric Imaging and Spectroscopy of the Corona
    from 400 to 1800 nm for Exploring the near Sun Plasma
Authors: Habbal, S. Rifai; Kuhn, J.; Mickey, D.; Jaeggli, S.; Morgan,
   H.; Roussev, I.; Johnson, J.; Arndt, M. B.; Daw, A.; Nayfeh, M. H.
Bibcode: 2006spse.conf...27H
Altcode:
  No abstract at ADS

Title: Infrared Coronal Polarimetry: Magnetometry and More
Authors: Kuhn, J.; Lin, H.; Jaeggli, S.; Arnaud, J.; Mickey, D.
Bibcode: 2006cosp...36.1643K
Altcode: 2006cosp.meet.1643K
  Near-infrared spectropolarimetry of the solar corona is a powerful tool
  for measuring the coronal magnetic field and even the local interstellar
  wind Here we describe how sensitive imaging spectropolarimetric
  observations are being obtained from the worlds largest coronagraph --
  a reflecting off-axis telescope -- from the summit of Haleakala Hawai i

Title: Using Imaging Infrared Coronal Spectropolarimetry to Measure
    the Near-Sun Plasma
Authors: Kuhn, J.; Lin, H.; Arnaud, J.; Jaeggli, S.
Bibcode: 2005AGUFMSH44A..08K
Altcode:
  A moderate aperture ground-based coronagraph and an imaging infrared
  spectropolarimeter have provided our first direct longitudinal coronal
  magnetograms. This talk will describe the advantages and subtleties of
  these techniques for direct coronal magnetometry. We also summarize
  some of the diagnostic potential of current and likely future IR
  spectropolarimetric instruments (like the Advanced Technology Solar
  Telescope) for measuring the properties of the near-solar plasma.

Title: Searching for Moving Magnetic Features at 1565 nm
Authors: Jaeggli, S. A.; Penn, M. J.; Henney, C. J.
Bibcode: 2005AGUSMSP41B..01J
Altcode:
  Spectropolarimetric data of the active region 10663 was taken with
  the CSUN-NSO IR camera and the McMath-Pierce telescope on August 26,
  2004 from 16:35 to 21:02 UT. Utilizing the Zeeman split Fe I line near
  1565 nm, the data is processed to remove instrumental polarization
  and a Milne-Eddington inversion technique is applied. The results of
  the inversion are used to examine the physical properties and radial
  motions of moving magnetic features which appear to originate in the
  sunspot penumbra.

Title: Moving Magnetic Features Inside the Penumbra of NOAO 10008
Authors: Luszcz, S. H.; Penn, M. J.; Jaeggli, S. A.; Henney, C. J.
Bibcode: 2005AGUSMSP11A..05L
Altcode:
  Over 30 years of observations and theories comprise the study of moving
  magnetic features (MMFs). MMFs, which often occur in opposite polarity
  pairs, migrate radially outward through the sunspot moat at speeds of
  about 1 km~s-1. A sequence of sixteen scans of the active region NOAO
  10008 were taken using the NSO-CSUN IR camera at the NSO McMath-Pierce
  Solar Telescope on 24 June 2002 17:38-21:59. Using the Fe I absorption
  line at 1564.8nm, magnetogram images and maps of the magnetic field
  vector were produced, revealing magnetic features within the penumbra
  that appear to move radially outward at similar velocities and azimuth
  angles as those of MMFs in the moat. We use polar time slice images
  to measure the radial velocities of both types of features. This
  work is carried out through the National Solar Observatory Research
  Experiences for Undergraduate (REU) site program, which is co-funded
  by the Department of Defense in partnership with the National Science
  Foundation REU Program.

Title: The 1564.6nm CN Line in Sunspots
Authors: Penn, M. J.; Jaeggli, S. A.
Bibcode: 2005AGUSMSP11A..02P
Altcode:
  The line strength of CN absorption has been observed to vary with
  the continuum intensity within sunspots, and the Doppler shift of
  the CN line at 1564.6nm has been shown to reveal fast Evershed flows
  in the penumbra. We examine several sunspots observed from 2002-2005
  using intensity spectroscopy and spectropolarimetry to determine the
  line strength, plasma flow velocity, and the local magnetic field
  configuration as functions of position in these sunspots.

Title: IR Vector Magnetic Fields I: Instrumental Polarization
    Correction
Authors: Jaeggli, S. A.; Penn, M. J.
Bibcode: 2004AAS...204.3706J
Altcode: 2004BAAS...36R.709J
  Instrumental polarization is evident in the spectra of active
  region 10008 taken with the CSUN-NSO IR camera at the McMath-Pierce
  telescope on June 24, 2002. Several iron lines near 15650 Å in the
  spectra exhibit Zeeman splitting. Using a technique described by Kuhn
  et. al. (1994) the original polarization is restored. For all Zeeman
  split lines in the spectra the corrected Stokes profiles for the Q and
  U components show symmetry, while Stokes V is made antisymmetric with
  no central component. <P />The observed Stokes vector is related to the
  true Stokes vector through the formula S<SUB>true</SUB> = M<SUP>-1</SUP>
  S<SUB>obs</SUB> where M<SUP>-1</SUP> is the inverse Mueller matrix. The
  correction coefficients from the Kuhn method are used to compute the
  inverse Mueller matrix for light path of the entire system. The expected
  inverse Mueller matrix is computed for the telescope at each scan time
  using a simple model described by Bernasconi (1997) but assuming the
  n and k values of the index of refraction are the same for each mirror
  surface. A least squares technique is used to fit this telescope model
  to the measured inverse Mueller matrix for the system. The telescope
  model can account for most of the measured cross-talk except for the
  observed Stokes Q to Stokes V cross-talk which is thought to occur in
  the polarimeter.

Title: IR Vector Magnetic Fields II: Atomic and Molecular Line
    Polarization in a Sunspot
Authors: Penn, M. J.; Jaeggli, S. A.; Henney, C. J.; Walton, S. R.;
   Ceja, J. A.
Bibcode: 2004AAS...204.3705P
Altcode: 2004BAAS...36..709P
  Full Stokes I,Q,U and V measurements of the active region NOAA 10008
  were taken from 21-27 June 2002 at the NSO Kitt Peak McMath/Pierce
  solar telescope using the CSUN/NSO HgCdTe IR camera and polarimeter at
  1565nm. The data is corrected for instrumental polarization as discussed
  in Paper I. Here the initial analysis of the atomic and molecular
  line polarization data is presented. <P />Inversion of the Fe I g=3
  1564.8nm line data with a modified Skumanich and Lites Milne-Eddington
  technique is used to measure photospheric magnetic field parameters. A
  sequence of scans covering several hours of time shows evolution of
  the magnetic field. Examination of the linear polarization of the OH
  1565.2nm shows curious temporal variation which results in a magnetic
  azimuth radically different from that measured using the photospheric
  lines. (Similar OH polarization behavior is seen in data from the
  CSUN San Fernando Observatory vacuum telescope taken with the CSUN/NSO
  camera in active region NOAA 10069 on 12 Aug 2002.) Finally, maps of
  the CN 1564.6nm Stokes I line shift show rapid penumbral Evershed
  flows and a curious signal in the sunspot umbra. <P />Some of this
  work is carried out through the National Solar Observatory Research
  Experiences for Undergraduate (REU) site program, which is co-funded
  by the Department of Defense in partnership with the National Science
  Foundation REU Program.

Title: An Online Astronomy Course VS. A Interactive Classroom
Authors: Slater, Timothy F.; Bailey, Janelle M.; Jaeggli, Sarah A.;
   Jones, Lauren V.; Lee, Ariane C.
Bibcode: 2003IAUSS...4E..27S
Altcode:
  Contemporary science education reforms emphasize building instruction
  around students’ pre-instructional beliefs fostering a learning
  environment where students interact with information and phenomena
  and providing students with frequent feedback to help them monitor
  their own learning. Recently personal computers and the Internet have
  given students access to scientific data sets and visualization tools
  that only professional scientists could use a few years before. With
  these things in mind we designed a hypermedia learning experience
  for introductory astronomy (Astronomy Online) that matches Internet
  technology with how people learn. Astronomy Online was used as the sole
  delivery system for courses offered during the Fall 2002 semester. The
  courses are run online. In one manifestation the course was delivered to
  middle and secondary school teachers spread across the globe. In another
  version the course was delivered to college undergraduate non-science
  majors where the only class meetings were a single orientation session
  and three on-campus exams. We compare these with on-campus courses
  that use highly interactive teaching techniques by studying common
  examination questions the Astronomy Diagnostic Test an attitude survey
  and interviews with students

Title: An Online Interactive Astronomy Course for Non-Science Majors
Authors: Slater, T. F.; Jones, L. V.; Bailey, J. M.; Jaeggli, S. A.;
   Lee, A. C.
Bibcode: 2002AAS...201.8803S
Altcode: 2002BAAS...34.1249S
  Contemporary science education reforms emphasize the need to build
  instruction around students' pre-instructional beliefs, to foster
  a productive learning environment for students to interact with
  information and phenomena, and to provide students with frequent
  feedback to help them monitor their own learning. Over the last five
  years, personal computers and the Internet have given students the
  opportunity to explore actual scientific data sets and use scientific
  visualization tools in ways that only professional scientists could
  only a few years before. Taken together, the authors have created
  a hypermedia learning experience for introductory astronomy that
  matches Internet technology with how people learn. This course weaves
  multimedia visualizations into a structured learning environment
  by dividing complex concepts into bite-size pieces. Each cognitive
  piece contains hyperlinks explaining all terms as well as illustrated
  using high-resolution images, animations, and videos which students
  manipulate to answer questions. Each module helps students engage in
  the pursuit of astronomy by providing activities where students make
  astronomical observations. Learners are required to answer pre-module
  questions, not as multiple-choice questions, but as written narratives,
  about the concept under study to make their knowledge explicit. At the
  conclusion, students compare new ideas with their initial answers and
  evaluate various alternative explanations. Astronomy Online was used
  as the sole delivery system for a course offered during the Fall 2002
  semester. The course was run online; the only class meetings were a
  single orientation session and three on-campus exams. We compare this
  with on-campus courses that use highly interactive teaching techniques
  by studying common examination questions, the Astronomy Diagnostic Test,
  an attitude survey, and interviews with students.

