Results 1 to 10 of about 334 (164)
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.
Jeffrey L. Linsky
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Stellar Chromospheric Activity [PDF]
Living Reviews in Solar Physics, 2008 The Sun, stars similar to it, and many rather dissimilar to it, have chromospheres, regions classically viewed as lying above the brilliant photosphere and characterized by a positive temperature gradient and a marked departure from radiative equilibrium.
Hall Jeffrey C.
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Evidence for stellar chromospheres in globular clusters [PDF]
Symposium - International Astronomical Union, 1987 We suggest that the conspicuous gaps frequently seen in the color-magnitude diagrams of globular clusters are caused by a sudden increase in chromospheric activity shortly after stars evolve away from the main sequence.
W. Liller, G. Alcaíno
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The Influence of Stellar Chromospheres and Coronae on Exoplanet Transmission Spectroscopy [PDF]
The Astrophysical Journal LettersA main source of bias in transmission spectroscopy of exoplanet atmospheres is magnetic activity of the host star in the form of stellar spots, faculae, or flares. However, the fact that main-sequence stars have a chromosphere and a corona and that these
Volker Perdelwitz +3 more
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Measuring the magnetic fields in the chromospheres of low-mass stars [PDF]
Nature CommunicationsMagnetic fields in the upper atmospheres of solar-like stars are believed to provide an enormous amount of energy to power the hot coronae and drive large-scale eruptions that could impact the habitability of planetary systems around these stars. However,
Tianqi Cang +13 more
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Stellar Chromospheric Variability [PDF]
Universe, 2021 Cool stars with convective envelopes of spectral types F and later tend to exhibit magnetic activity throughout their atmospheres. The presence of strong and variable magnetic fields is evidenced by photospheric starspots, chromospheric plages and ...
Richard de Grijs, Devika Kamath
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Heating of Stellar Chromospheres and Transition Regions [PDF]
Symposium - International Astronomical Union, 2004 To explain the heating of stellar chromospheres and transition regions, two classes of heating mechanisms have been considered: dissipation of acoustic and magnetic waves generated in stellar convection zones; and dissipation of currents generated by photospheric motions of surface magnetic fields.
Z. E. Musielak
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The Astrophysical Journal, 1978 A method is developed for estimating the nonradiative heating of stellar chromospheres by measuring the net radiative losses in strong Fraunhofer line cores. This method is applied to observations of the Mg II resonance lines in a sample of 32 stars including the sun.
J. L. Linsky, T. R. Ayres
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The Magnetic Field Configuration in Solar and Stellar Chromospheres [PDF]
Symposium - International Astronomical Union, 1983 Calculations are presented for the inhomogeneous magnetic field structure above a stellar photosphere which has magnetic flux tubes located at the downdraughts of its supergranulation pattern. Regions can be delineated where the ambient magnetic energy density is large or small compared with the thermal energy density derived from a model atmosphere ...
U. Anzer, D. J. Galloway
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The Astrophysical Journal, 1979 Models are constructed for the upper photosphere and chromosphere of Arcturus based on the H, K, and IR triplet lines of Ca II and the h and k lines of Mg II. The chromosphere model is derived from complete redistribution solutions for a five-level Ca II ion and a two-level Mg II ion. A photospheric model is derived from the Ca II wings using first the
Jeffrey L. Linsky +4 more
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