Author name code: bodnarova
ADS astronomy entries on 2022-09-14
author:"Bodnarova, Marcela" 
------------------------------------------------------------------------  

Title: The Effect of Area Averaging on the Approximated Profile of
    the H α Spectral Line
Authors: Bodnárová, M.; Utz, D.; Rybák, J.
Bibcode: 2016ASPC..504...23B
Altcode:
  The Hα line is massively used as a diagnostics of the
  chromosphere. Often one needs to average the line profile over some
  area to increase the signal to noise ratio. Thus it is important to
  understand how derived parameters vary with changing approximations. In
  this study we investigate the effect of spatial averaging of a selected
  area on the temporal variations of the width, the intensity and the
  Dopplershift of the Hα spectral line profile. The approximated profile
  was deduced from co-temporal observations in five points throughout
  the Hα line profile obtained by the tunable Lyot filter installed
  on the Dutch Open Telescope. We found variations of the intensity and
  the Doppler velocities, which were independent of the size of the area
  used for the computation of the area averaged Hα spectral line profile.

Title: Long-term trends of magnetic bright points. I. Number of
    magnetic bright points at disc centre
Authors: Utz, D.; Muller, R.; Thonhofer, S.; Veronig, A.; Hanslmeier,
   A.; Bodnárová, M.; Bárta, M.; del Toro Iniesta, J. C.
Bibcode: 2016A&A...585A..39U
Altcode: 2015arXiv151107767U
  Context. The Sun shows an activity cycle that is caused by its varying
  global magnetic field. During a solar cycle, sunspots, I.e. extended
  regions of strong magnetic fields, occur in activity belts that are
  slowly migrating from middle to lower latitudes, finally arriving
  close to the equator during the cycle maximum phase. While this
  and other facts about the strong extended magnetic fields have been
  well known for centuries, much less is known about the solar cycle
  evolution of small-scale magnetic fields. Thus the question arises
  if similar principles exist for small-scale magnetic fields. <BR />
  Aims: To address this question, we study magnetic bright points (MBPs)
  as proxies for such small-scale, kG solar magnetic fields. This study is
  based on a homogeneous data set that covers a period of eight years. The
  number of detected MBPs versus time is analysed to find out if there
  is an activity cycle for these magnetic features too and, if so, how
  it is related to the sunspot cycle. <BR /> Methods: An automated MBP
  identification algorithm was applied to the synoptic Hinode/SOT G-band
  data over the period November 2006 to August 2014, I.e. covering the
  decreasing phase of Cycle 23 and the rise, maximum, and early decrease
  of Cycle 24. This data set includes, at the moment of investigation, a
  total of 4162 images, with about 2.9 million single MBP detections. <BR
  /> Results: After a careful preselection and monthly median filtering
  of the data, the investigation revealed that the number of MBPs close
  to the equator is coupled to the global solar cycle but shifted in time
  by about 2.5 yr. Furthermore, the instantaneous number of detected MBPs
  depends on the hemisphere, with one hemisphere being more prominent,
  I.e. showing a higher number of MBPs. After the end of Cycle 23 and at
  the starting point of Cycle 24, the more active hemisphere changed from
  south to north. Clear peaks in the detected number of MBPs are found
  at latitudes of about ±7°, in congruence with the positions of the
  sunspot belts at the end of the solar cycle. <BR /> Conclusions: These
  findings suggest that there is indeed a coupling between the activity of
  MBPs close to the equator with the global magnetic field. The results
  also indicate that a significant fraction of the magnetic flux that
  is visible as MBPs close to the equator originates from the sunspot
  activity belts. However, even during the minimum of MBP activity,
  a percentage as large as 60% of the maximum number of detected MBPs
  has been observed, which may be related to solar surface dynamo action.

Title: The Košice meteorite fall: Recovery and strewn field
Authors: Tóth, Juraj; Svoreň, Ján; BorovičKa, Jiří Spurný,
   Pavel; Igaz, Antal; Kornoš, Leonard; Vereš, Peter; Husárik,
   Marek; Koza, Július; Kučera, Aleš Zigo, Pavel; Gajdoš, Štefan;
   Világi, Jozef; Čapek, David; Krišandová, Zuzana; Tomko, Šdušan;
   Ilha, Jiří Schunová, Eva; Bodnárová, Marcela; Búzová, Diana;
   Krejčová, Tereza
Bibcode: 2015M&PS...50..853T
Altcode: 2015M&PS..tmp..174T
  We provide the circumstances and details of the fireball observation,
  search expeditions, recovery, strewn field, and physical characteristics
  of the Košice meteorite that fell in Slovakia on February 28,
  2010. The meteorite was only the 15th case of an observed bolide with
  a recovered mass and subsequent orbit determination. Despite multiple
  eyewitness reports of the bolide, only three videos from security
  cameras in Hungary were used for the strewn field determination and
  orbit computation. Multiple expeditions of professionals and individual
  searchers found 218 fragments with total weight of 11.3 kg. The strewn
  field with the size of 5 × 3 km is characterized with respect to the
  space distribution of the fragments, their mass and size-frequency
  distribution. This work describes a catalog of 78 fragments, mass,
  size, volume, fusion crust, names of discoverers, geographic location,
  and time of discovery, which represents the most complex study of a
  fresh meteorite fall. From the analytical results, we classified the
  Košice meteorite as an ordinary H5 chondrite.

Title: Long time variations of Magnetic Bright Points observed
    by Hinode/SOT
Authors: Utz, D.; del Toro Iniesta, J. C.; Bellot-Rubio, L.;
   Bodnárová, M.; Muller, R.; Bárta, M.; Thonhofer, S.; Hanslmeier, A.
Bibcode: 2015CEAB...39...91U
Altcode:
  Magnetic bright points (MBPs) are manifestations of small-scale solar
  magnetic flux concentrations, best observable due to their high contrast
  in molecular bands like the G-band. Moreover, they are among the most
  interesting magnetic features to be studied in high spatial and temporal
  resolution in the solar photosphere. Their relevance for solar physics
  is not only given by their contribution to fundamental solar plasma
  physics on small scales but in addition due to their involvement in
  processes like the solar atmospheric heating problem (chromosphere
  and corona), their influence on granulation and hence the convective
  energy transport, as well as their contribution to the variations in
  total solar irradiance caused by their higher relative intensity. In
  this ongoing study we focus on the long-time evolution of statistical
  parameters of MBPs over the solar cycle. Are parameters like the mean
  intensity, average size/diameter, and number of MBPs per unit surface
  element variable with time? If so, how do these parameters vary and is
  there a relationship to the solar cycle? In the actual contribution
  we will discuss preliminary results regarding the variation of the
  number of MBPs with time. We saw a decrease in the number of MBPs for
  the first years of observation (2006 until 2011) with two distinct
  local minima in the years 2009 and 2011. After 2011 the number of MBPs
  is increasing again along with an increase in general solar activity
  (as seen by the number of sunspots, flares, and CMEs).

Title: On Dynamics of G-Band Bright Points
Authors: Bodnárová, M.; Utz, D.; Rybák, J.
Bibcode: 2014SoPh..289.1543B
Altcode: 2013arXiv1312.5464B
  Various parameters describing the dynamics of G-band bright points
  (GBPs) were derived from G-band images, acquired by the Dutch Open
  Telescope (DOT), of a quiet region close to the disk center. Our
  study is based on four commonly used diagnostics (effective velocity,
  change in the effective velocity, change in the direction angle, and
  centrifugal acceleration) and two new ones (rate of motion and time lag
  between recurrence of GBPs). The results concerning the commonly used
  parameters are in agreement with previous studies for a comparable
  spatial and temporal resolution of the used data. The most probable
  value of the effective velocity is ∼ 0.9 km s<SUP>−1</SUP>,
  whereas we found a deviation of the effective velocity distribution
  from the expected Rayleigh function for velocities in the range from
  2 to 4 km s<SUP>−1</SUP>. The change in the effective velocity
  distribution is consistent with a Gaussian one with FWHM=0.079 km
  s<SUP>−2</SUP>. The distribution of the centrifugal acceleration
  exhibits a highly exponential nature (a symmetric Gaussian centered
  at the zero value). To broaden our understanding of the dynamics of
  GBPs, two new parameters were defined: the real displacement between
  their appearance and disappearance (rate of motion) and the frequency
  of their recurrence at the same locations (time lag). For ∼ 45 % of
  the tracked GBPs, their displacement was found to be small compared to
  their size (the rate of motion smaller than one). The locations of the
  tracked GBPs mainly cover the boundaries of supergranules representing
  the network, and there is no significant difference in the locations
  of GBPs with small (m&lt;1) and large (m&gt;2) values of the rate of
  motion. We observed a difference in the overall trend of the obtained
  distribution for the values of the time lag smaller (slope of the trend
  line being −0.14) and greater (−0.03) than ∼ 7 min. The time
  lags mostly lie within the interval of ∼ 2 - 3 min, with those up to
  ∼ 4 min being more abundant than longer ones. Results for both new
  parameters indicate that the locations of different dynamical types
  of GBPs (stable/farther traveling or with short/long lifetimes) are
  bound to the locations of more stable and long-living magnetic field
  concentrations. Thus, the disappearance/reappearance of the tracked
  GBPs cannot be perceived as the disappearance/reappearance of their
  corresponding magnetic field concentrations.

Title: Density, porosity and magnetic susceptibility of the Košice
    meteorite shower and homogeneity of its parent meteoroid
Authors: Kohout, Tomáš; Havrila, Karol; Tóth, Juraj; Husárik,
   Marek; Gritsevich, Maria; Britt, Daniel; Borovička, Jiří; Spurný,
   Pavel; Igaz, Antal; Svoreň, Ján; Kornoš, Leonard; Vereš, Peter;
   Koza, Július; Zigo, Pavol; Gajdoš, Štefan; Világi, Jozef; Čapek,
   David; Krišandová, Zuzana; Tomko, Dušan; Šilha, Jiří; Schunová,
   Eva; Bodnárová, Marcela; Búzová, Diana; Krejčová, Tereza
Bibcode: 2014P&SS...93...96K
Altcode: 2014arXiv1404.1245K
  Bulk and grain densities, porosities, and magnetic susceptibilities
  of 67 individuals of Košice H chondrite fall were measured. The mean
  bulk and grain densities were determined to be 3.43 g/cm<SUP>3</SUP>
  with standard deviation (s.d.) of 0.11 g/cm<SUP>3</SUP> and 3.79
  g/cm<SUP>3</SUP> with s.d. 0.07 g/cm<SUP>3</SUP>, respectively. Porosity
  is in the range from 4.2% to 16.1%. The logarithm of the apparent
  magnetic susceptibility (in 10<SUP>-9</SUP> m<SUP>3</SUP>/kg) shows
  narrow distribution from 5.17 to 5.49 with mean value at 5.35 with
  s.d. 0.08. These results indicate that all studied Košice meteorites
  are of the same composition down to ~g scale without the presence of
  foreign (non-H) clasts and are similar to other H chondrites. Košice is
  thus a homogeneous meteorite fall derived from a homogeneous meteoroid.

Title: New insights into the temporal evolution of MBPs
Authors: Utz, D.; del Toro Iniesta, J. C.; Bellot Rubio, L. R.;
   Jurčak, J.; Thonhofer, S.; Bodnárová, M.; Hanslmeier, A.; Lemmerer,
   B.; Piantschitsch, I.; Guttenbrunner, S.
Bibcode: 2014CEAB...38...73U
Altcode:
  Magnetic bright points (MBPs) are among the most fascinating and
  interesting manifestations of small-scale solar magnetic fields. In the
  present work the temporal evolution of MBPs is followed in data sets
  taken by the Hinode satellite. The analysed data and obtained results
  confirm a recently presented study done with Sunrise/IMaX data, namely
  that MBPs are features undergoing fast evolution with magnetic fields
  starting around the equipartition field strength, then showing strong
  downflows (between 2 to 4 km/s) causing the magnetic field to amplify
  into the kG range (700 to 1500 G) before dissolving again. Furthermore
  the initial field inclinations depend on the initial magnetic field
  strengths and show an evolution with more vertical angles at some
  point during the evolution.

Title: Košice meteorite - recovery and the strew field
Authors: Toth, J.; Porubčan, V.; Borovička, J.; Igaz, A.; Spurný,
   P.; Svoreň, J.; Husárik, M.; Kornoš, L.; Vereš, P.; Zigo, P.;
   Koza, J.; Kučera, A.; Gajdoš, S.; Világi, J.; Čapek, D.; Šilha,
   J.; Schunová, E.; Krišandová, Z.; Tomko, D.; Bodnárová, M.;
   Búzová, D.; Krejčová, T.
Bibcode: 2012epsc.conf..708T
Altcode: 2012espc.conf..708T
  The glare of the bolide on the night of February 28, 2010,
  illuminated streets and interior of apartments, at some places in
  Eastern Slovakia and Northern Hungary and cannon-like burst or series
  of low frequency blasts were heard. Due to bad weather, cloudy skies
  and scatter showers the Central European Fireball Network (operated
  by Pavel Spurný of the Czech Academy of Sciences) did not take direct
  optical records of the bolide and also the Slovak Video Meteor Network
  (operated by Juraj Tóth of Comenius University in Bratislava) did
  not operate that night so that at first moment it seemed that there
  were no scientific records available of this event. Fortunately, fast
  photoelectric sensors on 7 automated fireball stations in the Czech
  Republic (6) and Austria (1) worked also under cloudy sky and recorded
  the light curve of the bolide. It enabled to determine the exact time
  and duration of the event and to estimate its brightness as well. The
  bolide reached the maximum brightness of at least -18 magnitudes in one
  huge flare. This light curve was used also for modeling of meteoroid
  atmospheric fragmentation. Later, several surveillance cameras data
  were published showing the moment when the night became a day. Three
  videos from Hungary (Örkény village, Fazzi Daniella and Vass Gábor;
  Telki village, contact persons Sárneczky Krisztián, Kiss László and
  Budapest) actually captured the fireball itself. Thanks to calibration
  of videos by several members of the Hungarian Astronomical Association
  (MCSE - www.mcse.hu, namely by Igaz Antal) and the trajectory analysis
  done by Jiří Borovička gave the hope that significant number
  of meteorite fragments reached the surface. He also calculated the
  impact area western of the city of Košice in Eastern Slovakia. The
  data from the Local Seismic Network of Eastern Slovakia (Peter Moczo
  of the Comenius University) analyzed by Pavel Kalenda confirmed the
  atmospheric trajectory as well [1].

Title: Dynamika fotosférických jasných bodov v G-páse odvodená
použitím dvoch plne automatických algoritmov Title: Dynamika
    fotosférických jasných bodov v G-páse odvodená použitím dvoch
plne automatických algoritmov Title: Dynamics of photospheric bright
    points in G-band derived from two fully automated algorithms.
Authors: Bodnárová, M.; Rybák, J.; Hanslmeier, A.; Utz, D.
Bibcode: 2010nspm.conf...25B
Altcode:
  Concentrations of small-scale magnetic field in the solar photosphere
  can be identified in the G-band of the solar spectrum as bright
  points. Studying the dynamics of the bright points in the G-band
  (BPGBs) can also help in addressing many issues related to the
  problem of the solar corona heating. In this work, we have used
  a set of 142 specled images in the G-band taken by the Dutch Open
  Telescope (DOT) on 19 October 2005 to make a comparison of two fully
  automated algorithms identifying BPGBs: an algorithm developed by Utz
  et al. (2009, 2010), and an algorithm developed following the work
  of Berger et al. (1995, 1998). We then followed in time and space
  motion of the BPGBs identified by both algorithms and constructed the
  distributions of their lifetimes, sizes and speeds. The results show
  that both algorithms give very similar results for the BPGB lifetimes
  and speeds, but their results vary significantly for the sizes of the
  identified BPGBs. This difference is due to the fact that in the case of
  the Berger et al. identification algorithm no additional criteria were
  applied to constrain the allowed BPGB sizes. As a result in further
  studies of the BPGB dynamics we will prefer to use the Utz algorithm
  to identify and track BPGBs.

Title: Slnečná aktivita a kozmické 'iarenie: magnetické pole
Slnka a úroveň kozmického žiarenia Title: Slnečná aktivita a
kozmické 'iarenie: magnetické pole Slnka a úroveň kozmického
žiarenia Title: Solar activity and cosmic radiation: Sun's magnetic
    field and cosmic radiation levels.
Authors: Bodnárová, M.; Rybák, J.; Gömöry, P.; Kudela, K.
Bibcode: 2010nspm.conf..175B
Altcode:
  In this work we have analyzed the correlation of the Sun's magnetic
  activity and cosmic radiation levels during the period 1951-2004. As a
  solar magnetic activity indicator, affecting the cosmic radiation, we
  have chosen open magnetic field configurations which we characterized
  by an open magnetic flux factor (OMFF). The OMFF was calculated from
  the intensity measurements of the green coronal line. In calculations
  leading to the relation between the OMFF and galactic cosmic radiation
  (GCR) levels the cross-correlation of these datasets was used. The goal
  of this contribution was to find mainly time-dependent changes in the
  evolution of the OMFF and GCR correlation. In order to do so,besides
  the correlation calculations based on the long time series of the
  OMFF and GCR data covering the entire period 1951-2004 we have also
  calculated the correlation of the OMFF and GCR data from shorter periods
  (180 days). We have found that the cross-correlation evolution varies
  depending on the phase of the solar cycle. During the minimum the
  evolution is characterized by conspicuous periodicity with a period
  ~ 14 days and the cross-correlation function takes statistically
  significant values. During the maximum the period of the variations
  is not clear and the cross-correlation function takes low values that
  are not statistically significant.

Title: Dynamics of G-band bright points derived using two fully
    automated algorithms
Authors: Bodnárová, M.; Utz, D.; Rybák, J.; Hanslmeier, A.
Bibcode: 2010CEAB...34...25B
Altcode:
  Small-scale magnetic field concentrations (∼ 1 kG) in the solar
  photosphere can be identified in the G-band of the solar spectrum
  as bright points. Study of the G-band bright points (GBPs) dynamics
  can help us in solving several questions related also to the coronal
  heating problem. Here a set of 142 G-band speckled images obtained
  using the Dutch Open Telescope (DOT) on October 19, 2005 are used to
  compare identification of the GBPs by two different fully automated
  identification algorithms: an algorithm developed by Utz et al. (2009a,
  2009b) and an algorithm developed according to papers of Berger et
  al. (1995, 1998). Temporal and spatial tracking of the GBPs identified
  by both algorithms was performed resulting in distributions of
  lifetimes, sizes and velocities of the GBPs. The obtained results show
  that both algorithms give very similar values in the case of lifetime
  and velocity estimation of the GBPs, but they differ significantly
  in case of estimation of the GBPs sizes. This difference is caused
  by the fact that we have applied no additional exclusive criteria on
  the GBPs identified by the algorithm based on the work of Berger et
  al. (1995, 1998). Therefore we conclude that in a future study of the
  GBPs dynamics we will prefer to use the Utz's algorithm to perform
  identification and tracking of the GBPs in G-band images.

