Brown Dwarfs and Very Low Mass Stars

巴斯里博士将对褐矮星和极低质量恒星的性质进行观测研究。鉴于最近发现的其他恒星的极低质量伴星，他的研究是及时和重要的。他的研究计划有三个主要目标：1)在昂宿星团中寻找棕矮星，并利用它们估计棕矮星的质量分数，并结合恒星模型确定该星团的“锂年龄”；2)探索M星晚期自转速度与活动之间的关系；3)利用高分辨率光谱学提供的大气诊断方法，改善非常冷的主序恒星的模型大气。拟议的一系列主题利用了Keck和Lick的观测设施，PI可以进入这些设施。***

Basri, Gibor AST 96-18439 Dr. Basri will carry out an observational study of the properties of brown dwarfs and very low-mass stars. His study is timely and important in light of the recent discoveries of very low mass companions to other stars. His research plan has 3 primary objectives : 1) to search for brown dwarfs in the Pleiades star cluster and to use them to estimate the brown dwarf mass fraction and to establish the "lithium age" of the cluster in conjunction with stellar models, 2) to explore the relation between rotational velocity and activity in late M stars, and 3) to improve model atmospheres for very cool main-sequence stars through the use of atmospheric diagnostics provided by high- resolution spectroscopy. The proposed array of topics take advantage of the observational facilities at Keck and at Lick, to which the PI has access. ***