How Binary Companion Stars Impact Stellar Rotational Evolution

斯蒂芬妮道格拉斯被授予美国国家科学基金会天文学和天体物理学奖学金，在哈佛史密森天体物理中心进行研究和教育计划。 道格拉斯将观测数百颗双星（相互绕转的恒星），测量它们的物理特性。 这将使我们更好地了解恒星以及它们对行星的影响是如何随时间变化的。 除了这项研究，道格拉斯将提供天文学研究经验，从社会经济上处于不利地位的背景中学生和本科生从群体在科学中代表不足。 道格拉斯将研究一颗星星的自转周期与其伴星的接近程度之间的关系。 对疏散星团的观测表明，在给定年龄的恒星中，快速自转的恒星往往是双星。 这可能是因为潮汐效应作用了0.01 - 100亿年，或者在最初的1000万年里，双星伴星和原行星盘之间的相互作用。 这两种效应都会导致双星比单星旋转得更快，从而影响双星系统的角动量演化。 道格拉斯将结合联合收割机旋转周期和双星轨道参数来解释为什么快速旋转的恒星往往是双星。 道格拉斯将使用测光、光谱学和光变曲线来识别候选双星，以及新的径向速度观测来测量轨道。 这些数据将使她能够测试双星伴星如何随着时间的推移影响恒星旋转。 对于她工作的教育部分，道格拉斯将开发基于调查的活动，向中学生介绍二元和系外行星研究。 她还将为来自代表性不足背景的本科生提供与二元和系外行星研究相关的项目建议。

Stephanie Douglas is awarded an NSF Astronomy and Astrophysics Fellowship to conduct a program of research and education at the Harvard-Smithsonian Center for Astrophysics. Douglas will observe hundreds of binary stars (stars that orbit each other) to measure their physical properties. This will allow a better understanding of how stars---and their effects on planets---change with time. Alongside this research, Douglas will provide astronomy research experiences to middle school students from socioeconomically disadvantaged backgrounds and to undergraduate students from groups underrepresented in science. Douglas will study the relationship between a star's rotation period and the proximity of a companion. Observations of open clusters show that among stars of a given age, the rapid rotators tend to be binaries. This could be because of tidal effects acting over 0.01 - 10 billion years or interactions between the binary companion and the protoplanetary disk during the first 10 million years. Both effects would cause binary stars to rotate faster than single stars, thus affecting angular momentum evolution in the binary systems. Douglas will combine rotation periods and binary orbital parameters to explain why rapidly rotating stars tend to be binaries. Douglas will use photometry, spectroscopy, and light curves to identify candidate binaries as well as new radial velocity observations to measure orbits. These data will allow her to test how binary companions affect stellar rotation over time. For the educational component of her work, Douglas will develop inquiry-based activities to introduce middle school students to binary and exoplanet research. She will also advise undergraduate students from underrepresented backgrounds on projects related to binary and exoplanet research.