stellar atmospheres
Lecturer: R. Gratton
This course wishes to provide the basis on most important issues
concerning stellar atmospheres, and an adequate background to read and
understand papers on the most advanced topics in this field.
Topics:
Introduction to stellar atmospheres and the formation of continuum;
basic equations; transfer equation; example cases, initial conditions;
Milne problem; atmospheric models; numerical computation of
atmospheric models; the absorption coefficient; stability of radiative
equilibrium.
Spectral lines; absorbing lines, profiles and equivalent widths;
atomic lines, oscillator strengths; damping width and profile; Doppler
profile; Stark profile; formation of absortion lines in stellar
atmospheres; curve of growth; quantitative chemical analysis;
rotational profile.
Convection in 1-d classical models; mixing length approach; 3-d model
atmospheres; granulation and convection observational effects; 3-d
models for stars; results with 3-d models; limitations of 3-d models.
Structure of the atmosphere and acitivity; photosphere, chromosphere
and corona. Solar dynamo. Stellar activity: observations in the
optical, UV and X-ray. Connection between activity and
rotation. Doppler imaging.
Abundance analysis: examples and applications.