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

• 批准号: 9819777
• 负责人: Imants Platais
• 金额: $ 9.5万
• 依托单位: Yale University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-07-01 至 2001-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9819777&HistoricalAwards=false
• 关键词: Collaborative; Project; Deep; Astrometry; Photometry

ABSTRACTAST-9819777Platais, ImantsThis is a multi-pronged collaborative investigation of stellar open clusters. 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 or lack thereof; (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. This grant supports 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). The collaborating team will conduct the photometry portion of this investigation. It will yield UBVRI apparent magnitudes and color indices for cluster members to ~1% internal precision for all stars in the astrometric database, as well as fainter stars in these 8 clusters and 6 additional clusters. From this data, a 'present day mass function' will be determined for a wide range of cluster ages, richness, galactic position and metallicity.

这是一个对恒星疏散星团的多管齐下的合作研究。目标是为各种天体物理问题提供有用的线索和约束：(1)初始质量函数的形状及其普适性或缺乏；(2)恒星核心对流超调的程度；(3)银河系中的金属丰度梯度。该项目还将为精心挑选的疏散星系团样本建立一个高质量的天体测量、光度和光谱数据数据库。这笔赠款支持这项调查的天体测量部分。将获得8个关键疏散星系团的位置信息、自行和星系团成员的确定，这些星系团的视星等比之前的调查弱至少6个视星等(~250倍)，同时保持当前的自行精度极限(~0.005“/年)。合作小组将进行这次调查的测光部分。它将得出天体测量数据库中所有恒星的UBVRI视星等和颜色指数~1%的内部精度，以及这8个星系团和另外6个星系团中较暗的恒星。根据这些数据，将确定广泛的星系团年龄、丰富度、星系位置和金属丰度的‘现代质量函数’。