Collaborative Research: Open Clusters at the Interface of Stellar Evolution and Stellar Dynamics

长期以来，天文学家一直利用星团来了解恒星在束缚群中的轨道运动，并将其作为实验室来测试星星形成和恒星演化的想法。 动力学和恒星演化这两个领域曾经独立发展，但随着探测器技术和计算速度的进步，现在已经可以将这两个领域的研究整合起来，在此次合作研究中罗伯特·马修博士（威斯康星州-麦迪逊大学）和Imants Platais博士（约翰霍普金斯大学）将进行一系列的观测和理论研究，以解决恒星演化和动力学中的几个突出问题。 第一个目标是对年龄在1亿到70亿年之间的7个丰富的疏散星团中的单星星和双星星星群体进行全面普查。 这将通过精确测量微小的视切向运动和径向速度的多历元测量来实现。这些数据将提供高度可靠的三维运动学成员的确定整个进化集群人口。第二个目标是描述这些星团中近100颗蓝离散星和其他新发现的异常星的星族特征，重点是它们的双星、自转和恒星活动分布。 第三个目标是计算一个数组恒星运动模拟疏散星团的初始条件，特别是二进制人口，由年轻星团的观测指导。 模拟将与J. Hurley博士（澳大利亚斯温伯恩）和A. Sills（加拿大麦克马斯特）将合作通过碰撞产生异常恒星。综合大量不同年龄和质量的异常恒星的自转、恒星活动和双星数据，将使人们在恒星动力学和恒星演化的界面上对这些恒星的形成机制、内部结构和年龄有新的认识。通过提高未来天文学家的研究和教学技能，该研究计划将产生更广泛的影响，无论是在美国境内还是境外。这项研究将包括学生和博士后研究员，预计将产生三个研究生论文，几个本科论文，和暑期本科生的研究经验。 这项工作将与研究，教学和学习的整合中心，由马修指导的NSF学习和教学中心。Platais通过与台湾-波罗的海三边合作的联系，将协助那些基础设施和智力潜力快速发展的最近处于不利地位的国家的学生和年轻研究人员的教育、培训和研究。

Astronomers have long used stellar clusters to learn about the orbital motions of stars in bound groups and as laboratories for testing ideas of star formation and stellar evolution. The two fields of dynamics and stellar evolution have developed independently, but with advances in detector technology and computing speed, it is now possible to integrate these two areas of research.In this collaborative study, Dr. Robert Mathieu (University of Wisconsin - Madison) and Dr. Imants Platais (Johns Hopkins University) will undertake a series of observational and theoretical investigations to address several outstanding questions in stellar evolution and dynamics. The first objective is to obtain a comprehensive census of the single star and binary star populations in seven rich open clusters which have ages from 100 million to 7 billion years. This will be accomplished through precise measurements of minute apparent tangential motions and multi-epoch measurements of radial velocities. These data will provide highly reliable three-dimensional kinematic membership determinations for the entire evolved cluster population. The second objective is to characterize the populations of nearly 100 blue stragglers and other newly discovered anomalous stars in these clusters, focusing on their binary, rotation and stellar activity distributions. The third objective is to compute an array stellar motion simulations for open clusters with initial conditions, especially the binary population, guided by observations of young stellar clusters. The simulations will be performed in collaboration with Dr. J. Hurley (Swinburne, Australia), and Dr. A. Sills (McMaster, Canada) will collaborate on the production of anomalous stars through collisions. The union of comprehensive rotational, stellar activity and binary data for a large set of anomalous stars of different ages and masses will allow new insights on formation mechanisms, internal structures, and ages of these stars at the interface of stellar dynamics and stellar evolution.The research plan will have a broader impact through enhancement of the research and teaching skills of future astronomers, both within and beyond the borders of the United States. This research will include students and a postdoctoral fellow, and is expected to yield three graduate dissertations, several undergraduate theses, and research experiences of summer undergraduate students. This work will be associated with the Center for the Integration of Research, Teaching, and Learning, an NSF Center for Learning and Teaching directed by Mathieu. Platais, through his association with the trilateral Taiwan-Baltic collaboration, will assist in the education, training and research of students and young researchers in recently disadvantaged countries that have fast developing infrastructure and intellectual potential.