Collaborative Research: Understanding exoplanets orbiting fully convective stars with the Habitable-zone Planet Finder

合作研究：利用宜居带行星探测器了解围绕全对流恒星运行的系外行星

• 批准号: 2108569
• 负责人: Ryan Terrien
• 金额: $ 4.56万
• 依托单位: Carleton College
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-09-01 至 2024-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2108569&HistoricalAwards=false
• 关键词: Collaborative; Research; Understanding; exoplanets; orbiting

The team will use the Habitable-zone Planet Finder (HPF), a Doppler spectrometer on the 10-m Hobby-Eberly Telescope, to conduct a survey of Class M red dwarf stars within 8 parsecs of Earth, as well as stars smaller than Class M4 further from Earth. The team will attempt to identify exoplanets in these systems from characteristic radial velocity (RV) color fluctuations in light emitted by the host stars. The exoplanet population around these smaller stars is poorly understood. The team seeks to answer the question of what exoplanetary systems look like around fully convective stars, and whether there is an increase in the fraction of super-Earths around lower-mass host stars. The team hopes to build a population of targets for follow-up imaging by upcoming Extremely Large Telescopes. The team will conduct a variety of outreach activities, including a teacher workshop at the MacDonald Observatory, mentorships at UC Irvine for students from under-represented groups, and participation on the HPF blog. The team will also train graduate students as part of the work.The HPF survey will provide data principally to answer two questions. First, the team will determine the occurrence rates for exoplanets orbiting fully-convective stars as a function of planet size and orbital period. Previous exoplanet surveys have shown that M dwarfs typically host small planets, and there is tenuous evidence that the frequency of larger super-Earth and Neptune-sized planets increases for mid-to-late M stars. However, these surveys are still dominated by early-M subtypes (more massive stars); this survey will offer empirical evidence for the planet population of the fully-convective end of the M type. Second, the team will tackle the problem of stellar jitter. Astrophysical noise, or "jitter," originating from stellar magnetic activity is rapidly becoming the limiting noise source in RV measurements, and M dwarfs are no exception. However, fully convective stars have poorly understood magnetic dynamos and very red spectral energy distributions. This means both the magnetic phenomena on their surfaces and the observables used to diagnose them may differ from those of Sunlike stars. With its stable instrument profile and NIR wavelength coverage, HPF will provide critical insights into jitter phenomena and support sophisticated models of its contribution.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.

该团队将使用10米Hobby-Eberly望远镜上的多普勒光谱仪，即可移动带行星HPF，对距离地球8秒差距内的M类红矮星以及距离地球更远的小于M4类的恒星进行调查。该团队将试图从宿主恒星发出的光的特征径向速度（RV）颜色波动中识别这些系统中的系外行星。这些较小恒星周围的系外行星群知之甚少。该团队试图回答这样一个问题：在完全对流的恒星周围，系外行星系统看起来是什么样的，以及在低质量的宿主恒星周围，超级地球的比例是否会增加。该团队希望通过即将到来的超大望远镜建立一个目标群进行后续成像。该团队将开展各种外展活动，包括在麦克唐纳天文台的教师研讨会，在加州大学欧文分校为代表性不足的群体的学生提供辅导，以及参与HPF博客。该小组还将培训研究生作为工作的一部分。HPF调查将提供数据，主要回答两个问题。首先，研究小组将确定围绕完全对流恒星运行的系外行星的出现率，作为行星大小和轨道周期的函数。以前的系外行星调查表明，M矮星通常拥有小行星，并且有微弱的证据表明，在M恒星的中后期，更大的超级地球和海王星大小的行星的频率增加。然而，这些巡天仍然以M早期的子类型（更大质量的恒星）为主;这次巡天将为M型完全对流端的行星人口提供经验证据。其次，该团队将解决恒星抖动的问题。来自恒星磁场活动的天体物理噪声或“抖动”正在迅速成为RV测量中的限制噪声源，M矮星也不例外。然而，完全对流的恒星对磁发电机和非常红的光谱能量分布知之甚少。这意味着它们表面的磁现象和用于诊断它们的观测值可能与太阳恒星不同。凭借其稳定的仪器配置和近红外波长覆盖范围，HPF将提供对抖动现象的关键见解，并支持其贡献的复杂模型。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

The Warm Neptune GJ 3470b Has a Polar Orbit

温暖的海王星 GJ 3470b 有极地轨道

• DOI: 10.3847/2041-8213/ac6e3c
• 发表时间: 2022
• 期刊: The Astrophysical Journal Letters
• 作者: Stefansson Gudmundur;Mahadevan Suvrath;Petrovich Cristobal;...;Hirano Teruyuki;et al.
• 通讯作者: et al.

GJ 3929: High-precision Photometric and Doppler Characterization of an Exo-Venus and Its Hot, Mini-Neptune-mass Companion

• DOI: 10.3847/1538-4357/ac8480
• 发表时间: 2022-07
• 期刊: The Astrophysical Journal
• 作者: C. Beard;Paul Robertson;S. Kanodia;J. Lubin;C. Cañas;Arvind F. Gupta;R. Holcomb;Sinclaire Jones;J. Libby-Roberts;Andrea S. J. Lin;S. Mahadevan;G. Stef'ansson;C. Bender;C. Blake;W. Cochran;M. Endl;Mark Everett;E. Ford;C. Fredrick;S. Halverson;L. Hebb;Dan Li;S. Logsdon;J. Luhn;M. McElwain;A. Metcalf;J. Ninan;J. Rajagopal;Arpita Roy;Mary C. Schutte;C. Schwab;R. Terrien;J. Wisniewski;J. Wright

Rotational Modulation of Spectroscopic Zeeman Signatures in Low-mass Stars

低质量恒星光谱塞曼特征的旋转调制

• DOI: 10.3847/2041-8213/ac4fc8
• 发表时间: 2022
• 期刊: The Astrophysical Journal Letters
• 作者: Terrien, Ryan C.;Keen, Allison;Oda, Katy;Stefánsson, Guðmundur;Mahadevan, Suvrath;Robertson, Paul;Ninan, Joe P.;Beard, Corey;Bender, Chad F.
• 通讯作者: Bender, Chad F.

TOI-1696 and TOI-2136: Constraining the Masses of Two Mini-Neptunes with the Habitable-Zone Planet Finder

• DOI: 10.3847/1538-3881/ac69ec
• 发表时间: 2022-04
• 期刊: The Astronomical Journal
• 作者: C. Beard;Paul Robertson;S. Kanodia;J. Libby-Roberts;C. Cañas;Arvind F. Gupta;R. Holcomb;Sinclaire Jones;H. Kobulnicky;Andrea S. J. Lin;J. Lubin;M. Maney;B. Parker;G. Stefansson;W. Cochran;M. Endl;L. Hebb;S. Mahadevan;J. Wisniewski;C. Bender;S. Diddams;M. Everett;C. Fredrick;S. Halverson;F. Hearty;A. Metcalf;A. Monson;J. Ninan;Arpita Roy;Mary C. Schutte;C. Schwab;R. Terrien