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

合作项目：关键疏散星团的深层天体测量和光度测量：恒星天体物理学的新基础

• 批准号: 9819768
• 负责人: Ata Sarajedini
• 金额: $ 16.5万
• 依托单位: Wesleyan University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-07-01 至 2001-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9819768&HistoricalAwards=false
• 关键词: Collaborative; Project; Deep; Astrometry; Photometry

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.

Sarajedini，Ata“合作项目：关键疏散星团的深度天体测量和光度测量：恒星天体物理的新基础”AST-9819768这是与耶鲁大学Imants Platais(AST-9819777)对恒星疏散星团进行的多管齐下的合作研究。其目的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适性；(2)恒星核心对流超调的程度；以及(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天体测量、光度学和光谱数据的数据库，这将为许多无关的未来研究提供基准。这笔赠款支持这项调查的测光部分。对于天体测量数据库中的所有恒星，以及这8个星系团和另外6个星系团中较暗的恒星，星系团成员的UBVRI视星等和颜色指数将被获得~1%的内部精度。合作小组将进行这次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以前的调查弱至少6个(~250倍)，同时保持目前的自行精度极限(~0.005“/年)。根据这些数据，将确定目前恒星按质量的分布，包括星系团的年龄、丰富度、银河系位置和金属丰度。