Asteroseismic analyses of the physics red-giant interiors

对恒星的研究在天体物理学中是极其重要的：几乎所有对我们的星系和其他星系的研究都是通过观测星光来完成的。我们银河系中恒星的性质--它们的化学丰度、年龄和动力学--被用来研究它的化学和动力学演化。虽然化学丰度可以通过光谱学获得，动力学性质可以通过专门的观测来测量，例如由GAIA等卫星提供的观测，但年龄要复杂得多，因为它们依赖于模型。利用一种名为星震学的尖端技术，研究恒星的地震行为，并结合观测和理论方法，该项目将通过澄清发生在恒星内部的一些最重要的物理过程，显著改进和加强恒星结构和演化的基本理论。反过来，这将使恒星的性质，包括年龄估计，更加精确。这些结果还可以更好地校准恒星年龄和各种元素丰度之间的关系。该项目通过一个以公开讲座、研讨会和暑期实习为基础的雄心勃勃的外展计划而得到丰富，这是脚手架方法的三个组成部分，旨在增加年轻学生对STESS的参与并支持他们过渡到大学。该计划得到了久负盛名的“耶鲁科学之路”项目的支持，也是该项目的一部分。该项目将把重点放在演化恒星、亚巨星和红巨星上，它们的年龄对研究银河系的化学动力学演化至关重要。主要目标是利用红巨星各自的恒星地震频率和周期间隔，研究影响红巨星结构的混合过程，如超调和湍流混合。该项目的第一部分是对不同混合过程产生的可观测地震特征的理论研究；第二部分是利用开普勒的恒星地震数据对演化的恒星进行地震研究，以检验恒星中实际发生的过程。这一奖项反映了美国国家科学基金会的法定任务，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

The study of stars is of paramount importance in astrophysics: almost all investigations of our Galaxy and other galaxies are done through the observation of starlight. Properties of stars in our Galaxy — their chemical abundances, ages, and dynamics — are used to study its chemical and dynamical evolution. While chemical abundances can be obtained from spectroscopy and dynamical properties can be measured by specialized observations such as those provided by satellites like Gaia, ages are much more complicated, because they are model dependent. Using a cutting-edge technique called asteroseismology, the study of the seismic behavior of stars, and combining both observational and theoretical methods, this project will significantly improve and enhance the basic theory of stellar structure and evolution by clarifying some of the most important physical processes that take place deep within stars. In turn, this will make stellar properties, including age estimates, more precise. The results will also allow better calibration of the relation between stellar ages and the abundance of various elements. The project is enriched by an ambitious outreach program based on public lectures, workshops, and summer internships, three components of a scaffolded approach aimed at increasing participation in STEMS for young students and supporting their transition to college. The plan is supported by, and is part of, the well-established and successful “Yale Pathways to Science” program. The project will focus on evolved stars, subgiants and red giants, the ages of which are vital in studying the chemo-dynamical evolution of the Galaxy. The primary goal is to examine the mixing processes, such as overshoot and turbulent mixing, that affect red giant structures, using the individual asteroseismic frequencies and period spacings of these stars. The first part of the project is a theoretical study of the observable seismic signatures produced by different mixing processes; the second is a seismic study of evolved stars with asteroseismic data from Kepler to examine what are the processes that actually take place in stars.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.