Results 141 to 150 of about 334 (164)
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Energy Balance in Solar and Stellar Chromospheres
1981The spectrum from a specific region of the sun or from a star can be used to determine the temperature-density stratification and other physical properties of the emitting atmospheric layers. We need such a description of the atmosphere in order to understand the causes of solar activity and the nature of various stellar phenomena.
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Theories of Heating of Solar and Stellar Chromospheres
1981In the outer atmosphere of stars a rise of the kinetic temperature to values above Teff is possible only if a large and persistent amount of mechanical heating is present. Constraints derived from empirical chromosphere models allow selection of important heating mechanisms from among a great number of possible processes.
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Stellar chromospheric activity in main-sequence stars
The research presented here presents a narrow slice of several largescale, ground-based astronomy surveys focused on chromospheric activity measurements of stars from the Keck Observatory. We conducted a comprehensive study analyzing chromospheric activity and its relationship with stellar properties in exoplanet host stars and solar neighborhood stars.openaire +1 more source
, 1993 Astrophysical properties and chromospheric activity of young stellar objects
In this talk I will address the problem of determining stellar parameters in young objects and measuring their magnetic activity level, which are strictly related. The photospheric/chromospheric activity produced by the stellar magnetic fields has indeed a strong impact, together with the mass accretion from circumstellar disks (when present), on the ...openaire +1 more source