Outer atmospheres of giant and supergiant stars

Abstract

The properties of the chromospheres, transition regions and coronae of cool evolved stars are reviewed based primarily on recent ultraviolet and X-ray studies. Recent determinations of mass loss rates using new observational techniques in the ultraviolet and radio spectral regions are discussed and observations indicating general atmospheric motions are considered. The techniques available for the quantitative modeling of these atmospheres are outlined and recent results discussed.