Collaborative Research: EXPRES Search for Low Mass Planets

合作研究：EXPRES 搜索低质量行星

• 批准号: 2009501
• 负责人: Joe Llama
• 金额: $ 15.53万
• 依托单位: Lowell Observatory
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-08-15 至 2024-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2009501&HistoricalAwards=false
• 关键词: Collaborative; Research; EXPRES; Search; Low

A collaborative team from Yale University, Lowell Observatory, and San Francisco State University will conduct a survey for small, temperate planets orbiting nearby stars. Virtually every star forms with planets. However, none of the planets so far detected are like the Earth. Many are gas giants, similar to Jupiter or Neptune. The only small rocky planets that have been detected orbit very close to their host stars, where inhospitable temperatures reach thousands of degrees. The discovery of other worlds that are similar to the Earth could help astronomers to find life on other planets. Unfortunately, the tiny signals from Earth-like planets are difficult to detect. This investigation will employ a new detector with the precision needed to detect potentially habitable worlds. The investigation will carry out a survey of bright, nearby stars with the goal of detecting planets that are similar to the Earth. This program places undergraduates and masters students from an officially recognized minority serving institution, with almost 41% of students having Chicano/Mexican or Latino background, at the forefront of exoplanet research. SFSU students will be collaborating with their peers at Yale and Lowell Observatory in observing, improving RV and planet atmosphere analysis tools, and improving understanding of planet formation. Students will also be learning to communicate these results with the Spanish speaking public and developing materials that can be shared outside of their community.The primary aim of this project is to detect low mass planets in both compact and Solar System like architectures. These planets have been missed by previous radial velocity surveys. This will allow the reconciliation of different planet populations seen by transit and radial velocity surveys and to better understand planet formation and evolution. The EXPRES spectrograph is calibrated with a stable laser frequency comb and has sufficient precision to find analogs of the small radius planets seen by Kepler transits. Following a carefully vetted set of 50 stars at high cadence over the next three years will allow the project find planets missed by transit surveys: these are small planets with orbital periods longer than 100 days. In addition, flexible scheduling of nearly 200 partial nights per year coupled with a remarkably stable instrumental profile enable Rossiter-McLaughlin measurements to determine orbital obliquity and detection of planet atmosphere constituents with high dispersion spectroscopy. The observational limitations of prior RV surveys and the unfavorable probability for detection of long period transits have left the occurrence rate of low-mass planets with periods longer than 10 days poorly constrained. At first glance the exoplanet populations appear to disagree for RV and transit surveys. The leap in radial velocity precision opens up an entirely new parameter space, allowing for detection of low mass planets in orbits longer than 40 days. It is likely that there are no other ways to detect these planets - this parameter space will be unexplored by current transit surveys. The investigation will reach the parameter space where Earth-like planets at habitable zone distances orbit around G and K stars. The highly stable measurements will also enable planet atmosphere studies and provide new insights into the behavior of stellar photospheres. The proposed survey will advance understanding of rocky planet occurrence rates and detect Earth-like planets in habitable orbits around Sun-like stars.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.

来自耶鲁大学、洛厄尔天文台和旧金山州立大学的一个合作小组将对围绕附近恒星运行的小型温带行星进行调查。几乎每颗恒星形成时都有行星。然而，到目前为止，没有一颗行星与地球相似。许多都是气态巨行星，类似于木星或海王星。唯一被探测到的小型岩石行星的轨道离它们的主星非常近，那里的温度高达数千度。与地球相似的其他世界的发现可以帮助天文学家在其他行星上找到生命。不幸的是，来自类地行星的微小信号很难被探测到。这项研究将使用一种新的探测器，其精度足以探测到潜在的宜居世界。这项调查将对附近明亮的恒星进行调查，目的是发现与地球相似的行星。该项目将来自官方认可的少数民族服务机构的本科生和硕士生安置在系外行星研究的最前沿，其中近41%的学生有墨西哥裔/墨西哥裔或拉丁裔背景。旧金山州立大学的学生将与耶鲁大学和洛厄尔天文台的同学合作，进行观测，改进RV和行星大气分析工具，并提高对行星形成的理解。学生还将学习将这些结果与讲西班牙语的公众交流，并开发可以在社区外共享的材料。这个项目的主要目的是在紧凑的和类似太阳系的结构中探测低质量行星。这些行星在之前的径向速度调查中被遗漏了。这将使凌日和径向速度测量所看到的不同行星种群得以协调，并更好地理解行星的形成和演化。express光谱仪使用稳定的激光频率梳进行校准，具有足够的精度，可以找到开普勒凌日观测到的小半径行星的类似物。在接下来的三年里，对50颗恒星进行高节奏的仔细审查，将使该项目能够发现凌日巡天遗漏的行星：这些行星是轨道周期超过100天的小行星。此外，每年近200个局部夜晚的灵活调度加上非常稳定的仪器剖面，使Rossiter-McLaughlin测量能够确定轨道倾角并使用高色散光谱检测行星大气成分。以往RV巡天观测的局限性和探测长周期凌日的不利可能性，使得周期超过10天的低质量行星的出现率很难得到约束。乍一看，系外行星的数量似乎不同意RV和凌日调查。径向速度精度的飞跃开辟了一个全新的参数空间，允许探测轨道超过40天的低质量行星。很可能没有其他的方法来探测这些行星——这个参数空间将不会被目前的凌日巡天探测到。调查将到达参数空间，在可居住区距离的类地行星围绕G和K恒星运行。高度稳定的测量还将使行星大气研究成为可能，并为恒星光球的行为提供新的见解。拟议中的调查将促进对岩石行星发生率的了解，并在类太阳恒星的宜居轨道上探测类地行星。该奖项反映了美国国家科学基金会的法定使命，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

Rossiter-McLaughlin detection of the 9-month period transiting exoplanet HIP41378 d

Rossiter-McLaughlin 探测到 9 个月周期的凌日系外行星 HIP41378 d

• DOI: 10.1051/0004-6361/202244182
• 发表时间: 2022
• 期刊: Astronomy & Astrophysics
• 影响因子: 6.5
• 作者: Grouffal, S.;Santerne, A.;Bourrier, V.;Dumusque, X.;Triaud, A. H.;Malavolta, L.;Kunovac, V.;Armstrong, D. J.;Attia, O.;Barros, S. C.
• 通讯作者: Barros, S. C.

Radial-velocity discovery of a second planet in the TOI-1338/BEBOP-1 circumbinary system

TOI-1338/BEBOP-1 环双星系统中第二颗行星的径向速度发现

• DOI: 10.1038/s41550-023-01948-4
• 发表时间: 2023
• 期刊: Nature Astronomy
• 影响因子: 14.1
• 作者: Standing, Matthew R.;Sairam, Lalitha;Martin, David V.;Triaud, Amaury H.;Correia, Alexandre C.;Coleman, Gavin A.;Baycroft, Thomas A.;Kunovac, Vedad;Boisse, Isabelle;Cameron, Andrew Collier
• 通讯作者: Cameron, Andrew Collier

Spectroscopy of TOI-1259B – an unpolluted white dwarf companion to an inflated warm Saturn

TOI-1259B 的光谱——一颗未受污染的白矮星伴星，是膨胀的温暖土星

• DOI: 10.1093/mnras/stac2879
• 发表时间: 2022
• 期刊: Monthly Notices of the Royal Astronomical Society
• 影响因子: 4.8
• 作者: Fitzmaurice, Evan;Martin, David V.;Rodríguez Martínez, Romy;Vallely, Patrick;Stephan, Alexander P.;Boley, Kiersten M.;Pogge, Rick;El-Badry, Kareem;Kunovac, Vedad;Triaud, Amaury H. M. J.
• 通讯作者: Triaud, Amaury H. M. J.

The EBLM project – IX. Five fully convective M-dwarfs, precisely measured with CHEOPS and TESS light curves

EBLM 项目 – IX。

• DOI: 10.1093/mnras/stac2565
• 发表时间: 2022
• 期刊: Monthly Notices of the Royal Astronomical Society
• 影响因子: 4.8
• 作者: Sebastian, D.;Swayne, M. I.;Maxted, P. F. L.;Triaud, A. H. M. J.;Sousa, S. G.;Olofsson, G.;Beck, M.;Billot, N.;Hoyer, S.;Gill, S.
• 通讯作者: Gill, S.

EXPRES. II. Searching for Planets around Active Stars: A Case Study of HD 101501

• DOI: 10.3847/1538-3881/abc41e
• 发表时间: 2020-10
• 期刊: The Astronomical Journal
• 作者: S. Cabot;R. Roettenbacher;G. Henry;Lily L. Zhao;R. Harmon;D. Fischer;J. Brewer;J. Llama;R. R. P