Collaborative Project: Deep Astrometry and Photometry of Key Open Clusters: A New Foundation For Stellar Astrophysics

“合作项目：关键疏散星团的深度天体测量和光度测量：恒星天体物理学的新基础”ast - 9819778这是与耶鲁大学Imants Platais对恒星疏散星团进行的多管齐下的合作研究（AST-9819777）。目标是为各种天体物理问题提供有用的线索和约束，例如：(1)初始质量函数的形状及其普遍性；(2)恒星核心对流超调程度；(3)银河系的金属丰度梯度。该项目还将为精心挑选的疏散星团样本建立一个高质量的天体测量学、光度学和光谱学数据数据库，为许多不相关的未来研究提供基准。这笔拨款支持这项研究的光度测定部分。星团成员的UBVRI视星等和显色指数将在天文测量数据库中获得~1%的内部精度，包括这8个星团和另外6个星团中较暗的恒星。合作小组将负责这次调查的天体测量部分。将获得8个关键疏散星团的位置信息、正常运动和星团成员的确定，至少比以前的调查暗淡6个视星等（~250倍），同时保持当前正常运动精度的限制（~0.005“/年）。根据这些数据，目前恒星的质量分布将在很大范围内确定星团年龄、丰富度、星系位置和金属丰度。

ABSTRACTSarajedini, Ata"Collaborative Project: Deep Astrometry and Photometry of Key Open Clusters: A New Foundation for Stellar Astrophysics"AST-9819768This is a multi-pronged collaborative investigation of stellar open clusters with Imants Platais at Yale University (AST-9819777). The goal is to provide useful clues and constraints on a variety of astrophysical problems such as: (1) the shape of the Initial Mass Function and its universality; (2) the extent of convective overshoot in stellar cores; and (3) the metallicity gradient in the Galaxy. The project will also result in a database of high quality astrometric, photometric and spectroscopic data for a carefully chosen sample of open clusters that will provide a benchmark for many unrelated future studies. This grant supports the photometry portion of this investigation. UBVRI apparent magnitudes and color indices for cluster members will be obtained to ~1% internal precision for all stars in the astrometric database, as well as for fainter stars in these 8 clusters and 6 additional clusters. The collaborating team will conduct the astrometry portion of this investigation. Positional information, proper motions and cluster membership determinations will be acquired for 8 key open clusters to at least 6 apparent magnitudes (~250x) fainter than previous surveys, while maintaining current limits of proper motion accuracy (~0.005 "/yr). From this data, the present distribution of stars by mass will be determined for a wide range of cluster ages, richness, galactic position and metallicity.