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

这个研究项目将提高我们对低质量恒星（质量小于太阳80%的恒星）的认识。该团队将对近200颗食双星的质量和半径进行极其精确的测量。这些测量结果将推动恒星理论模型的改进。这些模型被广泛应用于天体物理学科，它们对于描述天文学家正在发现的大量系外行星尤为重要。需要精确的恒星模型来评估地球质量行星的可居住性，随着下一代系外行星搜索开始明确瞄准低质量恒星，这个项目的结果将特别及时。宾夕法尼亚州立大学和维拉诺瓦大学的合作涉及本科生、研究生和博士后研究人员在研究的各个方面，两个团队的成员都积极参与公共宣传活动。该计划的主要目标是测量双星的质量和半径，精度优于3%，同时也表征了恒星的组成。这种测量精度对于解决目前模型预测和少数现有测量结果之间5-15%的低质量恒星的公认差异是必要的。这些测量是通过NASA开普勒天文台的超精确光度测量和团队收集的近红外和可见波长光谱仪（APOGEE， HYDRA， HRS）的广泛高分辨率地面光谱来实现的。数据分析采用尖端算法光曲线建模（PHOEBE），多维径向速度测量（TODCOR/TRICOR）和马尔可夫链蒙特卡罗技术评估稳健和可重复的参数和参数不确定性。这个项目的结果将使低质量恒星的数量增加一倍以上，包括精确的质量和半径测量，以及光谱测定的成分。

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.