Results 41 to 50 of about 881 (218)

Heating and dynamics of the quiet solar chromosphere [PDF]

Proceedings of the International Astronomical Union, 2007
AbstractThe quiet solar chromosphere in regions with negligible magnetic field is believed to be heated by acoustic waves. But their energy flux, measured in the upper photosphere with the Transition Region And Coronal Explorer (TRACE), has been found to be insufficient to account for the radiative emission from the chromosphere. Wedemeyer-Böhm et al. (
openaire   +1 more source

Approximations for radiative cooling and heating in the solar chromosphere [PDF]

Astronomy & Astrophysics, 2012
accepted for publication in Astronomy & ...
Carlsson, M., Leenaarts, J.
openaire   +2 more sources

Nine Outstanding Questions of Solar Wind Physics

Journal of Geophysical Research: Space Physics, Volume 125, Issue 7, July 2020., 2020
Abstract In situ measurements of the solar wind have been available for almost 60 years, and in that time plasma physics simulation capabilities have commenced and ground‐based solar observations have expanded into space‐based solar observations. These observations and simulations have yielded an increasingly improved knowledge of fundamental physics ...
Nicholeen M. Viall, Joseph E. Borovsky
wiley   +1 more source

Lyman‐alpha Variability During Solar Flares Over Solar Cycle 24 Using GOES‐15/EUVS‐E

Space Weather, Volume 18, Issue 7, July 2020., 2020
Abstract The chromospheric Lyman‐alpha line of neutral hydrogen (Lyα; 1216 Å) is the strongest emission line in the solar spectrum. Fluctuations in Lyα are known to drive changes in planetary atmospheres, although few instruments have had the ability to capture rapid Lyα enhancements during solar flares.
Ryan O. Milligan, Hugh S. Hudson, Phillip C. Chamberlin, Iain G. Hannah, Laura A. Hayes   +4 more
wiley   +1 more source

Quantifying Poynting Flux in the Quiet Sun Photosphere

The Astrophysical Journal, 2023
Poynting flux is the flux of magnetic energy, which is responsible for chromospheric and coronal heating in the solar atmosphere. It is defined as a cross product of the electric and magnetic fields, and in ideal MHD conditions it can be expressed in ...
Dennis Tilipman, Maria Kazachenko, Benoit Tremblay, Ivan Milić, Valentin Martínez Pillet, Matthias Rempel   +5 more
doaj   +1 more source

Rotation of solar‐like stars in the immediate solar neighborhood

Astronomische Nachrichten, Volume 341, Issue 5, Page 497-507, June 2020., 2020
Abstract Although photometric space‐based missions such as CoRoT or Kepler have yielded rotation measurements of many thousands of late‐type stars during the last decade, the rotational properties of the bulk of the G star population remain undetected by these missions.
Jürgen H. M. M. Schmitt, Marco Mittag
wiley   +1 more source

Chromospheric Bubbles in Solar Flares

, 2020
We analyze a grid of radiative hydrodynamic simulations of solar flares to study the energy balance and response of the atmosphere to nonthermal electron beam heating.
Mathioudakis, Michail, Zhigulin, Bogdan, Carlsson, Mats, Reid, Aaron   +3 more
core   +1 more source

Observational study of chromospheric heating by acoustic waves [PDF]

, 2020
Aims. Our aim is to investigate the role of acoustic and magneto-acoustic waves in heating the solar chromosphere. Observations in strong chromospheric lines are analyzed by comparing the deposited acoustic-energy flux with the total integrated radiative
Švanda, M., Koza, J., M. García-Rivas, P. Heinzel, H. Balthasar, M. Verma, Heinzel, P., C. Kuckein, Verma, M., D. Korda, Korda, D., Sobotka, M., M. Sobotka, C. Denker, I. Kontogiannis, J. Koza, M. Švanda, Abbasvand, V., V. Abbasvand, Denker, C., Balthasar, H., Kontogiannis, I., García-Rivas, M., Kuckein, C.   +23 more
core   +1 more source

Model solar chromosphere with prescribed heating

The Astrophysical Journal, 1989
Computed model solar chromospheres for prescribed departures from radiative equilibrium are specified in terms of the local mechanical (nonradiative) heat input. The computations are fully non-LTE and include millions of spectral lines. From the variety of models considered, the requirements on the heat input for a positive temperature gradient, dT/dh,
Lawrence S. Anderson, R. Grant Athay
openaire   +1 more source

Spectral signatures of bright grains determine chromospheric heating

Astronomy & Astrophysics
Chromospheric heating is an important ingredient in the energy budget of the solar atmosphere. Quantifying chromospheric heating from observations is a challenging task because spectral observations suffer from non-LTE effects, and heating events may ...
Udnæs Elias R., Pereira Tiago M. D.
doaj   +1 more source