CAREER: Fundamental properties of young and pre-main-sequence stars

事业：年轻恒星和前主序恒星的基本特性

• 批准号: 2143763
• 负责人: Andrew Mann
• 金额: $ 63.5万
• 依托单位: University of North Carolina at Chapel Hill
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-04-01 至 2027-03-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2143763&HistoricalAwards=false
• 关键词: CAREER; Fundamental; properties; young; pre

Stars form the foundation upon which much of modern astronomy rests and directly impact sub- fields as diverse as the cosmic distance scale, galaxy structure and evolution, the synthesis of chemical elements, planet formation, and the origin of life. Precise knowledge of basic stellar parameters such as mass, radius, age, and luminosity are thus essential. However, substantial gaps in this knowledge exist for young, low-mass stars due to the paucity of known eclipsing and astrometric binary stars among this population that enable accurate determinations of these quantities. The proposed research will derive accurate luminosities, radii, ages, and masses for young, low-mass stars using binary systems recently identified by Gaia, K2, and TESS surveys. This project will also support research activities by a graduate and several undergraduate students, as well as efforts by the principal investigator to develop interactive activities for astronomy courses and an interactive/multimedia-based exhibit based on this research for the Morehead Planetarium on the UNC Chapel Hill campus.The researchers will derive stellar parameters to better than 5% accuracy for 5-500 million year old K & M stars through the analysis of light curves in a sample of low-mass eclipsing and astrometric binary systems. This is a proven method that is routinely applied to older, more massive stars. Using these systems as ``benchmarks’’ they will derive empirical mass-luminosity-age relations, investigate the impact of magnetic activity on the derived parameters, and determine empirical relations for stellar radii, luminosity, and surface temperature from direct observables given an age. They will further explore age distributions in star clusters using spectroscopically determined lithium abundances and through explicit modeling of multiple populations. A major motivation of this work is to provide improved parameters for young planetary hosts, however the derived relations between direct observables and fundamental properties will be applicable to a wide variety of scientific applications.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.

恒星构成了现代天文学的基础，并直接影响到宇宙距离尺度、星系结构和演化、化学元素的合成、行星形成和生命起源等不同的子领域。因此，对恒星基本参数如质量、半径、年龄和光度的精确了解是必不可少的。然而，在这方面的知识存在很大的差距，年轻的，低质量的恒星，由于缺乏已知的日食和天体测量双星之间的人口，使这些数量的准确测定。拟议的研究将使用最近由盖亚，K2和TESS调查确定的双星系统来获得年轻，低质量恒星的准确光度，半径，年龄和质量。该项目还将支持一名研究生和几名本科生的研究活动，以及首席研究员为天文学课程开发互动活动的努力，以及基于该研究的一个基于互动/多媒体的展览，该展览将在位于伦敦查佩尔山校园的莫尔黑德天文馆举行。研究人员将通过分析低质量食和天体测量双星系统样本中的光变曲线，获得5- 5亿年前K M星的恒星参数，精度优于5%。这是一种经过验证的方法，通常应用于更老，更大质量的恒星。使用这些系统作为“基准”，他们将得出经验的质量-光度-年龄关系，研究磁活动对导出参数的影响，并确定恒星半径，光度和表面温度的经验关系，从给定的年龄直接观测。他们将进一步探索年龄分布在星星集群使用光谱测定的锂丰度和通过明确的建模多个人口。这项工作的一个主要动机是为年轻的行星宿主提供改进的参数，然而，直接观测和基本属性之间的关系将适用于各种各样的科学应用。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进行评估的支持。

项目成果

Using the Gaia Excess Uncertainty as a Proxy for Stellar Variability and Age

使用盖亚过度不确定性作为恒星变率和年龄的代理

• DOI: 10.3847/1538-4357/ace044
• 发表时间: 2023
• 期刊: The Astrophysical Journal
• 作者: Barber, Madyson G.;Mann, Andrew W.
• 通讯作者: Mann, Andrew W.

A Lithium Depletion Age for the Carina Association

Carina 协会的锂耗尽时代

• DOI: 10.3847/1538-3881/ad03f3
• 发表时间: 2023
• 期刊: The Astronomical Journal
• 作者: Wood, Mackenna L.;Mann, Andrew W.;Barber, Madyson G.;Bush, Jonathan L.;Milburn, Reilly P.;Thao, Pa Chia;Schmidt, Stephen P.;Tofflemire, Benjamin M.;Kraus, Adam L.
• 通讯作者: Kraus, Adam L.

Quantifying the Transit Light Source Effect: Measurements of Spot Temperature and Coverage on the Photosphere of AU Microscopii with High-resolution Spectroscopy and Multicolor Photometry

• DOI: 10.3847/1538-4357/ad0bed
• 发表时间: 2023-10
• 期刊: The Astrophysical Journal
• 作者: W. Waalkes;Z. Berta-Thompson;Elisabeth Newton;A. Mann;Peter Gao;H. Wakeford;L. Alderson;P. Plavchan

TESS Hunt for Young and Maturing Exoplanets (THYME). IX. A 27 Myr Extended Population of Lower Centaurus Crux with a Transiting Two-planet System

• DOI: 10.3847/1538-3881/aca8fc
• 发表时间: 2022-12
• 期刊: The Astronomical Journal
• 作者: M. Wood;A. Mann;Madyson G. Barber;Jonathan L. Bush;A. Kraus;B. Tofflemire;A. Vanderburg;E. Newton;G. Feiden;G. Zhou;L. Bouma;S. Quinn;David J Armstrong;A. Osborn;V. Adibekyan;E. D. Mena;S. Sousa;Jonathan Gagn'e;M. J. Fields;Reilly P. Milburn;P. C. Thao;S. P. Schmidt;C. Gnilka;S. Howell;N. Law;C. Ziegler;C. Briceño;G. Ricker;R. Vanderspek;D. Latham;S. Seager;J. Winn;J. Jenkins;J. Schlieder;H. Osborn;J. Twicken;D. Ciardi;Chelsea X. Huang

Hazy with a Chance of Star Spots: Constraining the Atmosphere of Young Planet K2-33b

• DOI: 10.3847/1538-3881/aca07a
• 发表时间: 2022-11
• 期刊: The Astronomical Journal
• 作者: P. C. Thao;A. Mann;P. Gao;Dylan A. Owens;A. Vanderburg;E. Newton;Yao Tang;M. J. Fields;T. David;J. Irwin;T. Husser;D. Charbonneau;S. Ballard