Mathieu, Robert AST 97-31302 Dr. Mathieu will carry out a program of high-precision radial velocity surveys of 4 key open clusters spanning a range of ages and metallicities. The surveys will provide a complete census of short period binary populations in these clusters, which will allow the PI to address a wide variety of issues in stellar astrophysics and cluster dynamics. The PI will make use of the WIYN telescope using its multi-object spectrograph in the survey. This radial velocity study is a component of the WIYN Open Cluster Study (WOCS), a project to carry out comprehensive photometric, spectroscopic and astrometric studies of a select set of open clusters, and provides both supporting data for later investigations and samples for immediate analysis. Among the issues the survey will address are : the nature of binary populations within these clusters, including the possible evolution of binary frequency with age and measures of main-sequence tidal circularization rates, dynamical evolution and mass segregation in clusters, the effect binarity has on stellar angular momentum evolution and internal mixing through its manifestation in light element abundances, and tests of stellar evolution theory through analysis of cluster color-magnitude diagrams free of field star contamination and binary members. ***
