RUI: Asteroseismology of pulsating Subdwarf B stars via observational mode identification and modeling

RUI：通过观测模式识别和建模研究脉动亚矮星 B 星的星震学

• 批准号: 1009436
• 负责人: Michael Reed
• 金额: $ 37.31万
• 依托单位: Missouri State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-09-01 至 2013-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1009436&HistoricalAwards=false
• 关键词: RUI; Asteroseismology; pulsating; Subdwarf; stars

As the study of pulsating subdwarf B (sdB) stars has developed, one overriding question has emerged: do they pulsate in high-degree modes where the number of nodal lines is greater than three? Models need to include such modes to account for the observed number of pulsations, but they are less likely to be observed because of geometric cancelation across the stellar surface. This has constrained the usefulness of the models for inferring the interior conditions of sdB stars. There is currently no answer to this controversial question about high-degree modes, but techniques such as multicolor photometry and time-series spectroscopy can be applied to provide that answer. To address these issues, this project will 1) obtain high-speed multicolor observations of at least six pulsating sdB stars; 2) obtain time-series spectroscopic data of at least two stars; 3) generate perturbed atmospheric models to interpret the observations; and 4) generate evolutionary models to match constrained modes and test the physics within sdB stars. Multicolor photometry is especially sensitive to high-degree modes, yet can be obtained from modest-sized telescopes. This work will critically test the current generation of models by determining if the predicted high-degree modes exist, and will produce models incorporating the latest theories to match the observations.Increasing the accuracy of sdB models will increase understanding of the cores inside most horizontal branch stars, and mass constraints will test evolution scenarios. The research involves undergraduate students, who will obtain, reduce, and analyze data and disseminate the results at conferences and in papers.

随着对脉动亚矮星 B (sdB) 恒星的研究不断深入，一个首要问题出现了：它们是否以节线数量大于 3 的高阶模式脉动？ 模型需要包括此类模式来解释观测到的脉动数量，但由于恒星表面的几何抵消，它们不太可能被观测到。 这限制了模型推断 sdB 恒星内部条件的有用性。 目前，关于高阶模式这个有争议的问题还没有答案，但可以应用多色光度测定和时间序列光谱等技术来提供答案。 为了解决这些问题，该项目将1）获得至少六颗脉动sdB恒星的高速多色观测； 2) 获得至少两颗恒星的时间序列光谱数据； 3）生成扰动大气模型来解释观测结果； 4) 生成演化模型来匹配约束模式并测试 sdB 恒星内的物理现象。 多色光度测定对高阶模式特别敏感，但可以通过中等尺寸的望远镜获得。 这项工作将通过确定预测的高阶模式是否存在来严格测试当前一代模型，并将产生结合最新理论以匹配观测结果的模型。提高 sdB 模型的准确性将增加对大多数水平分支内部核心的理解恒星和质量约束将测试进化场景。 该研究涉及本科生，他们将获取、减少和分析数据，并在会议和论文中传播结果。