High-Precision Radial-Velocity Surveys of Open Clusters

Mathieu博士将对4个关键疏散星团进行高精度径向速度调查，这些星团跨越了年龄和金属丰度的范围。这些调查将提供这些星团中短周期双星群的完整普查，这将使PI能够解决恒星天体物理学和星团动力学中的各种问题。PI将利用WIYN望远镜及其多目标摄谱仪进行调查。这项径向速度研究是WIYN疏散星团研究（WOCS）的一个组成部分，该项目对一组选定的疏散星团进行全面的光度、光谱和天文测量研究，为后续调查提供支持数据，并为即时分析提供样本。调查涉及的问题包括：这些星团内双星居群的性质，包括双星频率随年龄的可能演变和主层序潮汐圆化率的测量，星团内的动力演变和质量分离，双星对恒星角动量演变和内部混合的影响（通过其在轻元素丰度上的表现）。并通过分析星团的色星等图来验证恒星演化理论。＊＊＊

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. ***