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

来自约翰霍普金斯大学的一个由师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。如果不更好地了解行星的年龄，就无法回答与行星形成和演化有关的许多问题。据了解，恒星和它们的行星都有相同的年龄，但是大多数通常的方法来推断恒星的年龄对于拥有行星的恒星来说都是失败的，所以必须采取新的方法。获奖的研究将采用一种新的方法来推导恒星群体的年龄。这项新技术将被用来确定为什么一些行星系统与我们自己的不同。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，并将为博士论文奠定基础。此外，该小组将开始一个便携式天文馆访问几个巴尔的摩市以诺普拉特公共图书馆分支机构的计划。估计系外行星宿主星星年龄的困难是阻碍了解行星形成和演化的主要问题。传统的等时线法、星震法、陀螺年代法、恒星活动法或锂基年龄法对大多数行星宿主恒星的年龄估计是不可靠或不可用的，因此必须采取新的方法来解决系外行星宿主星星的年龄问题。随着薄盘恒星群体的年龄增长，其组成恒星由于与分子云、瞬变盘特征和银河棒的相互作用而经历随机踢击。调查将利用薄盘恒星群的银河系速度色散作为系外行星年龄的代理。该调查将使用这种银河系速度色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。对系外行星应用银河系速度色散技术可以揭示系外行星系统中重要恒星的起源，超短轨道周期行星的起源和命运，多行星系统经常被观测到的原因是该奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准。

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.