Atmospheric Evidence of Evolutionary Processes in Interacting Binaries

Abstract

The preceding invited paper by Sahade (1987) gave a balanced overall picture for the subject matter. I shall attempt to complement his talk in discussing two classes of atmospheric diagnostics of the evolutionary processes in interacting binary systems. These are: (I) Abnormal abundances of elements in the atmosphere resulting from the nuclear processes in the stellar interior. (II) Mass flow as a consequence of the evolution of either of the components and the Algol type binaries.There are several classes of objects with abundance anomalies, such as Am stars. At least some of these objects are known close binaries. In particular, most Am stars appear to be close binary stars. However, the physical causes of the metallic overabundances in those stars are still unclear. We shall in the following examine Algol type binaries for abundance anomalies.