Collaborative Research: A uniform sample of Kepler eclipsing binaries as benchmark stars to constrain stellar models and evolution at the bottom of the main sequence

合作研究：开普勒食双星的统一样本作为基准恒星，以约束主序列底部的恒星模型和演化

• 批准号: 1517592
• 负责人: Suvrath Mahadevan
• 金额: $ 30.24万
• 依托单位: Pennsylvania State Univ University Park
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-15 至 2019-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1517592&HistoricalAwards=false
• 关键词: Collaborative; Research; uniform; sample; Kepler

This research program will improve our understanding of low-mass stars (those with less than 80% of the Sun's mass). The team will obtain extremely precise measurements of the masses and radii of nearly 200 eclipsing binary stars. These measurements will drive improvements in theoretical models of stars. These models are used across a wide range of astrophysical disciplines, and they are particularly important for characterizing the tremendous number of exoplanets that astronomers are discovering. Accurate models of stars are needed to evaluate the habitability of Earth mass planets, and the results from this program will be particularly timely as the next generation of exoplanet searches begins explicitly targeting low-mass stars. This Penn State and Villanova collaboration involves undergraduate, graduate, and postdoctoral researchers in all facets of the research, and members of both teams actively participate in public outreach events.The primary objective of this program is to measure the mass and radius of binary stars with precision better than 3%, while also characterizing the stars' compositions. This measurement precision is necessary to address well recognized discrepancies for low-mass stars of 5-15% between predictions of current models and the handful of existing measurements. These measurements are achieved through the combination of ultra-precise photometry from NASA's Kepler observatory and extensive high-resolution ground-based spectroscopy from near-infrared and visible wavelength spectrographs (APOGEE, HYDRA, HRS) that have been collected by the team. Data are analyzed with cutting-edge algorithms for light-curve modelling (PHOEBE), multi-dimensional radial velocity measurements (TODCOR/TRICOR), and Markov Chain Monte Carlo techniques for assessing robust and repeatable parameters and parameter uncertainties. Results from this program will more than double the number of low-mass stars with both precision mass and radius measurements, and with spectroscopically determined compositions.

该研究计划将提高我们对低质量恒星（少于太阳质量的80％的恒星）的理解。 该小组将获得对近200个黯然失色的二进制恒星的质量和半径的极为精确的测量。 这些测量将推动恒星理论模型的改进。 这些模型在广泛的天体物理学科中使用，对于表征天文学家发现的大量系外行星尤其重要。 需要精确的恒星模型来评估地球质量行星的可居住性，并且随着下一代系外行星搜索开始明确靶向低质量恒星，该程序的结果将特别及时。这项宾夕法尼亚州立大学和维拉诺瓦的合作涉及研究的各个方面的本科，研究生和博士后研究人员，并且两支球队的成员都积极参加公共宣传活动。该计划的主要目标是衡量比3％更好的二进制恒星的质量和半径，同时还表征了星星的组成。 在当前模型的预测和少数现有测量值之间，这种测量精度对于解决5-15％的低质量恒星的良好差异是必要的。 这些测量是通过从NASA的开普勒天文台和广泛的高分辨率地面光谱从近红外和可见的波长光谱仪（Apogee，Hydra，HRS）组合来实现的。 用尖端曲线建模（Phoebe），多维径向速度测量值（Todcor/Tricor）和Markov链蒙特卡洛技术评估可靠，可重复的参数和参数不确定性，对数据进行了分析。 该程序的结果将是具有精度质量和半径测量以及光谱确定的组成的低质量恒星数量的两倍以上。

项目成果

A Sub-Neptune-sized Planet Transiting the M2.5 Dwarf G 9-40: Validation with the Habitable-zone Planet Finder

• DOI: 10.3847/1538-3881/ab5f15
• 发表时间: 2019-12
• 期刊: The Astronomical Journal
• 作者: G. Stefansson;C. Cañas;J. Wisniewski;Paul Robertson;S. Mahadevan;M. Maney;S. Kanodia;C. Beard-C.-Bear