On the chemical abundances of close binary stars on and near the main sequence

Abstract

A review is made of the chemical abundances of binary stars in the catalogs of Cayrel de Strobel (1981, 1985). Solar-type single-line close binaries, A- and B-type close binaries on and near the main sequence, and close binaries with spotted photospheres are considered. It is shown that ignorance of the binary condition introduces a bias into elemental abundance statistics which is of the order of the precision with which an abundance can be ordinarily established. It is also shown that specific-seeming abundance anomalies for hot and cool binaries might be explained by the existence of unrecognized binaries among the sample