Results 21 to 30 of about 938 (183)
International Astronomical Union Colloquium, 1980 Important progress in our understanding of stellar chromospheres has occurred in the past few years as a result of new observations, developments in spectral line formation theory, and the application of that theory to the construction of detailed model chromospheres.
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Investigating the Origin of the First Ionization Potential Effect With a Shell Turbulence Model
Frontiers in Astronomy and Space Sciences, 2021 The enrichment of coronal loops and the slow solar wind with elements that have low First Ionization Potential, known as the FIP effect, has often been interpreted as the tracer of a common origin.
Victor Réville +6 more
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Chromospheric Seismology [PDF]
Symposium - International Astronomical Union, 1988 The aim of the present study is to examine whether seismologic diagnostic techniques may be used to improve the models of the solar chromosphere. We are mainly concerned by oscillations observed in the cores of strong lines such as the resonance lines of Ca II or Mg II. It is intuitive, and confirmed by numerical simulations (Gouttebroze and Leibacher,
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Earth and Space Science, 2020 Solar prominences are structures of importance because of their role in polar field reversal. We study the long‐term variation of the time latitude distribution of solar prominences in this article.
Subhamoy Chatterjee +4 more
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, 1994 We show results from SO/Sacramento Peak data to discuss three issues: (i)--the spatial occurrence of chromospheric 3--min oscillations; (ii)--the validity of Ca II H&K line-center Doppler Shift measurements; (iii)--the signi ?cance of oscillation power and phase at frequencies above 10 mHz.
Lites, B.W., Rutten, R.J., Thomas, J.H.
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Spectropolarimetric fluctuations in a sunspot chromosphere [PDF]
Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, 2020 The instrumental advances made in this new era of 4 m class solar telescopes with unmatched spectropolarimetric accuracy and sensitivity will enable the study of chromospheric magnetic fields and their dynamics with unprecedented detail. In this regard, spectropolarimetric diagnostics can provide invaluable insight into magneto-hydrodynamic (MHD) wave ...
M. Stangalini +10 more
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Open Astronomy, 2021 We present intensity curves of solar flares obtained in the Hα hydrogen line and CaII H, CaIR 8542Å lines using multichannel spectrographs of Ondřejov Observatory (Czech Republic) for the period 2000–2012.
Kupryakov Yurij Alekseevich +5 more
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THE CHROMOSPHERE-LIKE ENVELOPE OF THE VARIABLE STAR T TAU
Odessa Astronomical Publications, 2017 The emission measure of the near-star chromosphere-like envelope of variable star T Tau with various mechanisms of radiation is computed. The normalization on the observed distribution of energy in continuum spectrum is carried out.
I. V. Shpychka, N. V. Virun
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Solar-Terrestrial Physics, 2018 We have studied Ca II K line profiles, using two time series of spectrograms taken in two regions near the solar disk center. In each of the regions, the spectrograph slit cut out several areas of the quiet region and a plage.
Turova I.P. +2 more
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Journal of Space Weather and Space Climate, 2020 We present the observing program proposed by Paris and Côte d’Azur Observatories for monitoring solar activity during the upcoming cycle 25 and providing near real time images and movies of the chromosphere for space-weather research and applications ...
Malherbe Jean-Marie +2 more
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