Exoplanet System Ages from Galactic Kinematics and their Impact on Planet Formation and Evolution

约翰·霍普金斯大学的一个由教职员工和学生组成的研究小组将测量围绕附近恒星运行的行星的年龄。如果不能更好地了解行星的年龄，就无法回答许多与行星形成和演化有关的问题。据了解，恒星和它们的行星具有相同的年龄，然而，大多数常用的推断恒星年龄的方法对拥有行星的恒星都无效，因此必须采取新的方法。获奖的研究将应用一种新的方法来计算恒星群的年龄。然后，这项新技术将被用来确定为什么一些行星系统与我们的不同。这项研究计划将为摩根州立大学和约翰霍普金斯大学的STEM本科生提供实习机会，并将形成博士论文的基础。此外，该小组还将启动一项便携天文馆参观计划，参观巴尔的摩市伊诺克普拉特公共图书馆的几个分馆。估计系外行星宿主恒星年龄的困难是阻碍在理解行星形成和演化方面取得进展的主要问题。传统的等时、星震、回旋时间、基于恒星活动或基于锂的年龄估计对于大多数行星宿主恒星来说是不可靠的或不可用的，因此必须采取新的方法来解决系外行星宿主恒星的年龄问题。随着薄盘恒星群的老化，其组成恒星由于与分子云、瞬变的盘特征和星系棒的相互作用而经历随机的撞击。这项研究将利用一个薄盘恒星群的银河系速度离散度作为系外行星年龄的替代。此次调查将使用这种银河系速度分散技术来计算具有不同特征的系外行星宿主恒星以及没有行星的恒星的相对年龄，以探索行星的形成和演化。对于系外行星的银河速度分散技术的应用可以揭示系外行星系统中显著恒星倾角的起源，超短轨道周期行星的起源和命运，以及多行星系统经常在平均运动共振范围内被观测到的原因。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。

A research group of faculty and students from Johns Hopkins University will measure the ages of planets orbiting nearby stars. Many questions related to planet formation and evolution cannot be answered without a better understanding of planet ages. It is understood that both stars and their planets have the same age, however most of the usual ways to infer stellar ages fail for stars that host planets, so new approaches must be taken. The awarded investigation will apply a new method to derive ages for populations of stars. This new technique will then be used to identify why some planetary systems are different from our own. This research program will provide internships for STEM undergraduates from Morgan State University as well as Johns Hopkins University, and it will form the basis for a PhD thesis. In addition, this group will start a program of portable planetarium visits to several Baltimore City Enoch Pratt Public Library branches. The difficulty of estimating exoplanet host star ages is a major problem preventing progress in understanding planet formation and evolution. Traditional isochrone, asteroseismic, gyrochronological, stellar activity-based, or lithium-based age estimates are unreliable or unavailable for most planet host stars, so new approaches must be taken to solve the problem of exoplanet host star ages. As a thin disk stellar population ages, its constituent stars experience random kicks due to interactions with molecular clouds, transient disk features, and the Galactic bar. The investigation will make use of the Galactic velocity dispersion of a thin disk stellar population as a proxy for exoplanet age. The investigation will use this Galactic velocity dispersion technique to calculate relative ages for exoplanet host stars with different characteristic, as well as stars without planets, to explore planet formation and evolution. The application of the Galactic velocity dispersion technique for exoplanets could reveal the origin of significant stellar obliquities in exoplanet systems, the origin and fate of ultra-short orbital period planets, and the reason that multiple-planet systems are often observed just wide of mean-motion resonances.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.