Green, Elizabeth AST 97-31655 In a collaborative effort, PIs Green and Liebert of the University of Arizona and PI Saffer of Villanova University will investigate the characteristics of binary systems among subdwarf B stars, the field counterparts to the extended and blue horizontal branch stars found in clusters. Using precise new radial velocity observations, they will investigate the frequency of binaries and the distribution of orbital parameters and masses of components of the binary systems. The ultimate goals of the research are to understand better the origin of subdwarf B stars, which make up the majority of very blue objects found in sky surveys and are an important contributor to the UV excesses observed in external galaxies, and, by analogy, the origin of the blue and extended horizontal branch stars seen in clusters. ***
