Results 131 to 140 of about 173,010 (211)

Potential Chromospheric Evaporation in the M Dwarf’s Flare Triggered by Einstein Probe Mission

The Astronomical Journal
Although flares from late-type main-sequence stars have been frequently detected in the multiwavelength, the associated dynamical process has been rarely reported so far.
J. Wang, X. Mao, C. Gao, H. Y. Liu, H. L. Li, H. W. Pan, C. Wu, Y. Liu, G. W. Li, L. P. Xin, S. Jin, D. W. Xu, E. W. Liang, W. M. Yuan, J. Y. Wei   +14 more
doaj   +1 more source

Theoretical studies of chromospheres and winds in cool stars [PDF]

Calculated radiative losses from H, H-, Ca II, and Mg II show that cooling for the chromosphere of the supergiant epsilon Gem do not differ greatly from the solar law, although there are differences at approximately 6000K due to ionization effects.
Dupree, A. K.
core   +1 more source

Partially Coherent Scattering in Stellar Chromospheres. V. Analytic Approximations Including Background Continuum Absorption [PDF]

, 2002
K. G. Gayley
openalex   +1 more source

First Direct Detection of Magnetic Fields in Starspots and Stellar Chromospheres [PDF]

, 2007
S. V. Berdyugina, D. M. Fluri, N. Afram, F. Suwald, P. Petit, J. Arnaud, David M. Harrington, J. R. Kuhn   +7 more
openalex   +1 more source

M dwarfs: Theoretical work [PDF]

Theoretical work on the atmospheres of M dwarfs has progressed along lines parallel to those followed in the study of other classes of stars. Such models have become increasingly sophisticated as improvements in opacities, in the equation of state, and ...
Mullan, Dermott J.
core   +1 more source

Mind the Gap. II. The Near-UV Fluxes of M Dwarfs

The Astronomical Journal
Because of the continuous variations in mass, metallicity, and opacity, dwarf stars are distributed along the main sequence on optical and near-IR color–magnitude diagrams following a smooth polynomial.
Wei-Chun Jao, Allison Youngblood
doaj   +1 more source

Asymmetry in zeta Auriage chromospheres [PDF]

Asymmetry in the ultraviolet spectra of zeta-Aur, similar to that reported in optical observations, was studied using IUE data. A plot of the integrated flux of zeta Aurigae from 1625 to 1675 A as a function of absolute phase shows no significant ...
Ahmad, I. A.
core   +1 more source

Stellar Library of Differential Emission Measures and Extreme Ultraviolet Spectra: Dwarf Stars Observed by the Extreme Ultraviolet Explorer

The Astrophysical Journal
Extreme ultraviolet (EUV; 100–912 Å) photons influence the formation and evolution of planets by ionizing hydrogen and other species, but the EUV radiation of most exoplanet host stars is poorly constrained.
Girish M. Duvvuri, Zachory K. Berta-Thompson, J. Sebastian Pineda, Kevin France, Alexander Brown, Allison Youngblood, David J. Wilson, Cynthia S. Froning, P. Christian Schneider, Thomas Ayres, Keivan G. Stassun   +10 more
doaj   +1 more source

The helium chromosphere, coronal holes, and stellar X-rays

The Astrophysical Journal, 1975
The solar chromosphere at the limb seen in D3 is an irregular bright band 1000 km thick with a dark band 1000 km thick beneath. The D3 chromosphere disappears in coronal holes. It is shown that the D3 emission, as well as the other He I and He II lines, can be explained quantitatively by photoionization by coronal back-radiation. A Chapman layer with N(
openaire   +1 more source

Empirical Prediction of Plasma Emission Measure Distributions and X-Ray/Extreme-ultraviolet Spectra of Late-type Stars

The Astrophysical Journal
High-energy emission spectra from the outer atmospheres of late-type stars represent an important feature of the stellar activity in several contexts, such as the photoevaporation and photochemistry of planetary atmospheres or the modeling of irradiated ...
A. Maggio, I. Pillitteri, J. Sanz-Forcada, G. Micela   +3 more
doaj   +1 more source