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

双星是星星形成过程中非常常见的自然产物，它作为恒星大小、质量、温度和光度的校准物，为恒星研究提供了重要的基础。它们也是恒星结构、形成和演化、潮汐相互作用和其他更专业领域的探测器，如吸积物理学、星震学、共振动力学以及多星星系统中系外行星的形成和演化。双食双星是一组特殊的双星，其中两颗恒星周期性地相互食，产生光变曲线的变化。SETI研究所和圣地亚哥州立大学的一个科学家小组将对这种特殊类型的双星的常规周期性行为进行分析。行星的存在、自转和潮汐力都可能引起偏差。通过调查这些偏差，该团队将能够约束每个组成星星的内部结构，为改进当前的恒星结构模型提供独特的约束条件。此外，该团队将为STEM教师创建一套为期3天的研讨会，与现有的国家教育推广计划合作，将天文学家与3至9年级的教师合作。讲习班将提供实践项目为基础的学习与日食和过境的总体主题。该项目计划有三个组成部分：1）测量数百个食双星数十年的周期变化; 2）将每个星星的内部结构限制在合适的双星中; 3）探测是否存在其他天体（恒星，环双星行星）。研究人员将利用所有来自地面和太空档案馆的光度数据来研究数百个已知的食双星。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特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拱点运动常数。这个项目有可能在更大的样本中测量每个星星的拱点运动常数。这将通过使用几十年来测量的日食时间来实现。这是至关重要的，因为岁差的时间尺度比双星的轨道周期长得多，因此，它们的探测往往需要几十年的测光观测。研究覆盖不同恒星类型和环境的食双星的大样本也将推进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转移。该奖项反映了NSF的法定使命，并被认为值得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来支持。

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.