Stellar Rotation and the Chronology of the Galaxy

恒星自转和银河年表

• 批准号: 1411685
• 负责人: Donald Terndrup
• 金额: $ 50.58万
• 依托单位: Ohio State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-01 至 2019-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1411685&HistoricalAwards=false
• 关键词: Stellar; Rotation; Chronology; Galaxy

Our understanding of how the universe around us changes with time is limited by our ability to measure ages of stars. Unlike other fundamental properties, this is not something that we are able to measure directly. We have some limited idea, at least in a statistical sense, for some stars - particularly those all formed together in "clusters". We have also developed sophisticated computer models that predict how other observed properties change in time, which we can compare to observations of real stars. Stars spin rapidly when they are formed, but their spin slows with time. A lot of effort is going into developing a better understanding of how this happens. The goal of "gyrochronology" is to be able to infer the age of a star by measuring how fast it spins, with careful consideration of its other measureable properties (not all stars with the same spin rate have the same age). This project will attempt to resolve many of the uncertainties through a careful comparison of theoretical models describing how stars spin down, measurements of long-period rotators (tens of days) using the unprecedented database from the Kepler spacecraft, and follow-up observations from ground-based observatories. The proposed activities will directly contribute to the training of a graduate student in observational and theoretical astrophysics, as well as advanced statistical analysis. It will also provide research opportunities for undergraduate students. The PI will also lead efforts to use the new Planetarium at Ohio State as a laboratory for data visualization.The CoPIs, along with a graduate student and two collaborators who are experts using the Kepler database, will conduct a careful observational and theoretical study with the goal of producing a well-calibrated rotation-age relation for field stars. This will be based on a more careful analysis of the properties of cluster stars, measurements of longer periods using Kepler data with follow-up observations at the MDM observatory at Kitt Peak, and detailed models of angular momentum loss in stars. It will benefit from the team's expertise in asteroseismology and statistics. Gyrochronology is being applied to a vast array of astrophysical problems, from planetary to extragalactic, yet there are serious complications involved in establishing a single-valued function between rotation rate and age. This team has identified all of the complications and laid out a plan that could lead to a well-constrained and widely-applicable gyrochronology law for field stars.

我们对周围宇宙如何随时间变化的理解受到我们测量恒星年龄的能力的限制。 与其他基本性质不同，这是我们无法直接测量的。 至少在统计学的意义上，我们对某些恒星--特别是那些在“星团”中一起形成的恒星--有一些有限的了解。 我们还开发了复杂的计算机模型，可以预测其他观测到的属性如何随时间变化，我们可以将其与真实的恒星的观测进行比较。 恒星在形成时自转速度很快，但随着时间的推移，自转速度会减慢。 人们正在努力更好地理解这种情况是如何发生的。 “陀螺年代学”的目标是能够通过测量星星的旋转速度来推断它的年龄，并仔细考虑它的其他可测量的属性（并非所有具有相同旋转速率的恒星都具有相同的年龄）。 该项目将试图通过仔细比较描述恒星如何自旋下降的理论模型、使用开普勒航天器前所未有的数据库测量长周期转子（数十天）以及地面观测站的后续观测来解决许多不确定性。 拟议的活动将直接有助于对一名研究生进行观测和理论天体物理学以及高级统计分析方面的培训。 它还将为本科生提供研究机会。 主要研究员还将领导使用俄亥俄州州立大学的新天文馆作为数据可视化实验室的工作。CoPI将与一名研究生和两名合作者（他们是开普勒数据库的专家）一起进行仔细的观测和理论研究，目标是为场星产生校准良好的旋转-年龄关系。 这将基于对星团恒星性质的更仔细分析，利用开普勒数据进行更长周期的测量，并在基特峰MDM天文台进行后续观测，以及详细的恒星角动量损失模型。 它将受益于该小组在星震学和统计学方面的专门知识。 陀螺年代学正被应用于从行星到河外星系的大量天体物理问题，但在建立旋转速率和年龄之间的单值函数时存在严重的并发症。 这个团队已经确定了所有的复杂性，并制定了一个计划，可以导致一个良好的约束和广泛适用的陀螺年代学定律的字段明星。