Studies of Hot Subdwarf Stars in Binary Systems

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。理查德·韦德博士将开展一项计划，对双星中的亚矮星B进行多历元径向速度观测，以确定它们的轨道是否与理论预测的一样。 亚矮星B是明亮、炽热的演化恒星，其核心正在进行氦的核聚变。 恒星演化理论和最近的观测表明，许多亚矮星B是在相互作用的双星系统中形成的。 将跟踪那些发现径向速度变化的系统，以确定完整的轨道;相反，如果许多系统在低测量阈值时没有可检测到的加速度，那么这类双星就不可能相互作用形成亚矮星B星星，观测将在霍比-埃伯利望远镜和国家设施上进行。 这项工作将提供基础数据，可用于把理论的双星星相互作用和亚矮星B的起源更坚实的基础。更好地了解可能成为亚矮星B的恒星的年龄和质量范围，对于解释星系在大的回望时间内发出的紫外线是很重要的。这项工作将有助于验证，挑战并最终改进用于预测或理解现代天体物理学中各种现象的二元人口合成模型。该项目将雇用和培训学生来执行大部分研究任务。将开始一系列新的经常和定期的晚间公开讲座。这将为非正式科学教育提供一条途径，以帮助维持一个有科学素养的民众。

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).Dr. Richard Wade will carry out a program of multi-epoch radial velocity observations of subdwarf B stars in binaries to establish whether their orbits are as predicted by theory. Subdwarf B stars are luminous, hot, evolved stars which are undergoing nuclear fusion of helium in their cores. Stellar evolution theory and recent observations suggest that many subdwarf B stars were formed in interacting binary systems. Those systems for which radial velocity variations are found will be followed to determine full orbits; conversely, if many systems show no detectable acceleration at a low measurement threshold, then this class of binaries cannot have interacted to form the subdwarf B star.The observations will be carried out at the Hobby-Eberly Telescope and at national facilities. This work will provide fundamental data that can be used to put the theory of binary star interactions and the origin of subdwarf B stars on a firmer basis. A better understanding of the ages and mass ranges of stars that can become subdwarf B stars is important in interpreting the ultraviolet light from galaxies at large lookback times. The work will help to validate, challenge, and ultimately improve binary population synthesis models that are used to predict or understand a wide variety of phenomena in modern astrophysics. The project will employ and train students to carry out a large portion of the research tasks. A new series of frequent and regular evening public talks will be initiated. This will provide a pathway for informal science education to help maintain a scientifically literate populace.