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: 2108512
• 负责人: Suvrath Mahadevan
• 金额: $ 28.43万
• 依托单位: Pennsylvania State Univ University Park
• 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=2108512&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.

该团队将使用可居住的区域搜索器（HPF），这是10米的爱好 - 浮游望远镜上的多普勒光谱仪，对地球8 parsecs中的M红矮星级恒星进行了调查，以及地球上的恒星在地球上更小于M4。该团队将尝试从这些系统中的外部行星中从宿主恒星发出的光中的特征性径向速度（RV）颜色波动中识别。这些较小的恒星周围的系外行星人口鲜为人知。该团队试图回答有关完全对流的明星周围哪种外球星系看起来像什么样的问题，以及在低质量宿主明星周围的超收入的比例增加。该团队希望通过即将到来的极大望远镜来建立一系列目标，以进行后续成像。该团队将进行各种宣传活动，包括麦克唐纳天文台的教师讲习班，在UC Irvine的指导中为来自代表性不足的小组的学生进行指导，以及参加HPF博客。该团队还将作为工作的一部分培训研究生。HPF调查将提供数据主要回答两个问题。首先，团队将确定绕行星大小和轨道时期的轨道全面恒星的外部球星的发生率。先前的系外行星调查表明，M矮人通常构成小行星，并且有很少的证据表明，较大的超级地球和海王星大小的行星的频率增加了中高恒星的恒星。但是，这些调查仍然由早期的亚型（较大的恒星）主导。这项调查将为M型完全对立端的星球人口提供经验证据。其次，团队将解决恒星抖动的问题。源自恒星磁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，而M矮人也不例外。然而，完全对流的恒星对磁发电机的了解鲜为人知，并且非常红色的光谱能分布。这意味着其表面上的磁现象和用于诊断它们的可观察物可能与阳光恒星的磁性现象不同。 HPF凭借其稳定的仪器概况和NIR波长的覆盖范围，将为抖动现象提供关键的见解，并支持其贡献的复杂模型。该奖项反映了NSF的法定任务，并被认为是值得通过基金会的知识分子优点和更广泛影响的审查标准通过评估来支持的。

项目成果

An In-depth Look at TOI-3884b: A Super-Neptune Transiting an M4Dwarf with Persistent Starspot Crossings

• DOI: 10.3847/1538-3881/accc2f
• 发表时间: 2023-02
• 期刊: The Astronomical Journal
• 作者: J. Libby-Roberts;Mary C. Schutte;L. Hebb;S. Kanodia;C. Cañas;G. Stefansson;Andrea S. J. Lin;S. Mahadevan;Winter Parts(they/them)-Winter-Parts(they-them)-2218517096;Luke Powers;J. Wisniewski;C. Bender;W. Cochran;S. Diddams;M. Everett;Arvind F. Gupta;S. Halverson;H. Kobulnicky;A. Kowalski;Alexander Larsen;A. Monson;J. Ninan;B. Parker;L. Ramsey;Paul Robertson;C. Schwab;T. Swaby;R. Terrien

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

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.

Characterization of Low-mass Companions to Kepler Objects of Interest Observed with APOGEE-N

• DOI: 10.3847/1538-4365/acbcbe
• 发表时间: 2023-02
• 期刊: The Astrophysical Journal Supplement Series
• 作者: C. Cañas;C. Bender;S. Mahadevan;D. Bizyaev;Nathan De Lee;S. Fleming;F. Hearty;S. Majewski;C. Nitschelm;D. Schneider;J. Serna;K. Stassun;G. Stefansson;G. Stringfellow;John C. Wilson

TOI-3785 b: A Low-density Neptune Orbiting an M2-dwarf Star

TOI-3785 b：绕 M2 矮星运行的低密度海王星

• DOI: 10.3847/1538-3881/acd8bf
• 发表时间: 2023
• 期刊: The Astronomical Journal
• 作者: Powers, Luke C.;Libby-Roberts, Jessica;Lin, Andrea S. J.;Cañas, Caleb I.;Kanodia, Shubham;Mahadevan, Suvrath;Ninan, Joe P.;Stefánsson, Guđmundur;Gupta, Arvind F.;Jones, Sinclaire
• 通讯作者: Jones, Sinclaire