Comprehensive Analysis of Period Changes in Eclipsing Binaries as a Probe of Stellar Astrophysics

食双星周期变化的综合分析作为恒星天体物理的探索

• 批准号: 2206814
• 负责人: Veselin Kostov
• 金额: $ 46.28万
• 依托单位: SETI Institute
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-09-01 至 2025-08-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2206814&HistoricalAwards=false
• 关键词: Comprehensive; Analysis; Period; Changes; Eclipsing

A natural and very common product of star formation processes, binary stars provide a vital foundation of stellar studies as calibrators for stellar sizes, masses, temperatures, and luminosities. They also serve as probes for stellar structure, formation and evolution, tidal interactions, and other more specialized fields such as accretion physics, asteroseismology, resonant dynamics, and the formation and evolution of exoplanets in multiple star systems. Eclipsing binaries are a special group of binary stars, in which the two stars periodically eclipse each other, producing variations in their light curves. A team of scientists at the SETI institute and at San Diego State University will perform an analysis of deviations from the regular, periodic behavior in this special type of binary stars. Deviations can be introduced by the presence of planets and by rotation and tidal forces. By investigating these deviations, the team will be able to constrain the internal structure of each component star, providing unique constraints to improve current stellar structure models. In addition, the team will create a set of 3-days workshops for STEM teachers, in collaboration with existing national education outreach programs that partner astronomers with teachers in grades 3 to 9. The workshops will provide hands-on project-based learning with an overarching theme of eclipses and transits. The project plan has three components: 1) Measure decades-long period changes for hundreds of eclipsing binaries; 2) Constrain the internal structure of each star in suitable binaries; 3) Probe for the presence of additional bodies (stars, circumbinary planets). The investigators will use all available photometric data from ground- and space-based archives for hundreds of known eclipsing binaries. Furthermore, they will use a state-of-the-art modeling code that predicts the measured eclipse times based on the orbital configuration of the particular system and the properties of its components, as well as on the corresponding tidal and general relativity effects. Presently, period changes in certain binaries are used to measure the average apsidal motion constant of the binary. This project has the potential to measure the apsidal motion constants of each star in a much larger sample. This will be made possible by using eclipse times measured over many decades. This is critical because the precession timescales are much longer than the orbital period of the binaries and, as a result, their detection often requires photometric observations spanning decades. Studying a large sample of eclipsing binaries covering different stellar types and environments will also advance the knowledge of the physics of binary interactions, leading to a better understanding of tidal forces, migration, spin-orbit coupling, and mass transfer.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

双星是恒星形成过程的自然且非常常见的产物，作为恒星大小、质量、温度和光度的校准器，为恒星研究提供了重要的基础。它们还可以作为恒星结构、形成和演化、潮汐相互作用以及其他更专业领域的探测器，例如吸积物理学、星震学、共振动力学以及多恒星系统中系外行星的形成和演化。食双星是一组特殊的双星，其中两颗恒星周期性地相互食，从而产生光变曲线的变化。 SETI 研究所和圣地亚哥州立大学的科学家团队将对这种特殊类型双星的常规、周期性行为的偏差进行分析。行星的存在以及自转和潮汐力都会引起偏差。通过研究这些偏差，该团队将能够约束每个组成恒星的内部结构，为改进当前的恒星结构模型提供独特的约束。此外，该团队还将与现有的国家教育推广计划合作，为 STEM 教师举办一系列为期 3 天的研讨会，该计划将天文学家与 3 至 9 年级的教师合作。这些研讨会将提供基于项目的实践学习，其总体主题是日食和凌日。该项目计划由三个部分组成：1）测量数百个食双星数十年的周期变化； 2）将每颗恒星的内部结构约束在合适的双星中； 3) 探测是否存在其他天体（恒星、环绕双星的行星）。研究人员将使用来自地面和太空档案中数百个已知食双星的所有可用光度数据。此外，他们将使用最先进的建模代码，根据特定系统的轨道配置及其组件的属性，以及相应的潮汐和广义相对论效应来预测测量的日食时间。目前，某些双星的周期变化被用来测量双星的平均近轴运动常数。该项目有可能在更大的样本中测量每颗恒星的背面运动常数。通过使用几十年来测量的日食时间，这将成为可能。这一点至关重要，因为进动时间尺度比双星的轨道周期长得多，因此，它们的探测通常需要跨越数十年的光度观测。研究覆盖不同恒星类型和环境的食双星的大样本也将增进对双星相互作用的物理学知识，从而更好地理解潮汐力、迁移、自旋轨道耦合和质量传递。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。