Wide Low-Mass Binaries: Coeval Laboratories for Testing the Formation and Evolution of Stars, and the Structure and Evolution of the Milky Way

该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。m型矮星（dm）约占银河系恒星的70%，其主序星的寿命比银河系的年龄还要长。因此，它们是银河系结构和演化的有用探测器。低质量双星是检验经验关系的重要的同步实验室，因为这两颗恒星可能是在同一时间由相同的物质形成的。该项目将构建迄今为止最大的宽低质量双星样本，然后利用这个样本：(a)研究多样性在低质量恒星形成中的作用；(b)测试和校准质量-年龄-活动-旋转关系，这种关系对确定恒星年龄至关重要，并用于确定系外行星宿主恒星的基本特性；(c)追溯银河系中动态相互作用的历史。在斯隆数字巡天中所有宽低质量双星的识别基础上，对这些双星的光谱观测、时间序列光度测定和自适应光学成像将解决以下问题。1)什么是低质量矮星活动的固有散射？2)低质量恒星的活动作为质量和时间的函数是什么？3) dm中年龄-活动的绝对关系是什么？4)随着时间的推移，宽二进制的存活率是多少？宽双星的组成部分是否与非宽系统中的低质量恒星具有相同的紧密的多重统计？项目团队在范德比尔特大学和菲斯克大学之间开展了一个联合项目，指导本科生、研究生和博士后的教育和研究，这大大提高和扩大了代表性不足的少数民族在天文学领域的参与。目前的研究包括继续和扩大本科和研究生课程的计划。它还包括一个优秀的专业发展机会，为博士后研究员寻求经验，整合研究和学生指导。

AST-0909463StassunThis award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).M-dwarfs (dMs) make up about seventy percent of the stars in our Galaxy and have main sequence lifetimes longer than the age of the Galaxy. They are therefore useful probes of the structure and evolution of the Milky Way. Low-mass binaries are important coeval laboratories for testing empirical relations, as the two stars likely formed from the same material at the same time. This project will construct the largest sample of wide low-mass binaries ever assembled, and then use this sample to: (a) study the role of multiplicity in the formation of low-mass stars; (b) test and calibrate the mass-age-activity-rotation relationships that are central to stellar age determinations and that are used to determine the basic properties of exoplanet host stars; and (c) trace the history of dynamical interactions in the Milky Way. Building on the identification of all wide low-mass binaries in the Sloan Digital Sky Survey, spectroscopic observations, time-series photometry, and adaptive optics imaging of these binaries will address the following questions. 1) What is the intrinsic scatter of activity in low-mass dwarfs? 2) What is the activity of low-mass stars as a function of mass and time? 3) What is the absolute age-activity relationship in dMs? 4) What is the survival rate of wide binaries over time? 5) Do the components of wide binaries have the same close multiplicity statistics as low-mass stars not in wide systems?The project team has a joint program between Vanderbilt and Fisk Universities of education and research mentoring at the undergraduate, graduate, and postdoctoral levels, which significantly enhances and broadens the participation of underrepresented minorities in astronomy. The present research includes a plan to continue and expand upon the undergraduate and graduate programs. It also includes an excellent professional development opportunity for a postdoctoral researcher seeking experience integrating research and student mentoring.