LHS 1815b: The First Thick-Disk Planet Detected By TESS
Tianjun Gan, Avi Shporer, John H. Livingston, Karen A. Collins, Shude Mao, Alessandro A. Trani, Davide Gandolfi, Teruyuki Hirano, Rafael Luque, Keivan G. Stassu… 展开作者
Tianjun Gan, Avi Shporer, John H. Livingston, Karen A. Collins, Shude Mao, Alessandro A. Trani, Davide Gandolfi, Teruyuki Hirano, Rafael Luque, Keivan G. Stassun, Carl Ziegler, Steve B. Howell, Coel Hellier, Jonathan M. Irwin, Jennifer G. Winters, David R. Anderson, César Briceño, Nicholas Law, Andrew W. Mann, Xavier Bonfils, Nicola Astudillo-Defru, Eric L. N. Jensen, Guillem Anglada-Escudé, George R. Ricker, Roland Vanderspek, David W. Latham, Sara Seager, Joshua N. Winn, Jon M. Jenkins, Gabor Furesz, Natalia M. Guerrero, Elisa Quintana, Joseph D. Twicken, Douglas A. Caldwell, Peter Tenenbaum, Chelsea X. Huang, Pamela Rowden, Bárbara Rojas-Ayala
We report the first discovery of a thick-disk planet, LHS 1815b (TOI-704b, TIC 260004324), detected in the TESS survey. LHS 1815b transits a bright (V = 12.19 mag, K = 7.99 mag) and quiet M dwarf located $ 29.87\pm0.02 pc$ away with a mass of $0.502\pm0.015 M_{\odot}$ and a radius of $0.501\pm0.030 R_{\odot}$. We validate the planet by combining space and ground-based photometry, spectroscopy, and imaging. The planet has a radius of $1.088\pm 0.064 R_{\oplus}$ with a $3 σ$ mass upper-limit of $8.7 M_{\oplus}$. We analyze the galactic kinematics and orbit of the host star LHS1815 and find that it has a large probability ($P_{thick}/P_{thin} = 6482$) to be in the thick disk with a much higher expected maximal height ($Z_{max} = 1.8 kpc$) above the Galactic plane compared with other TESS planet host stars. Future studies of the interior structure and atmospheric properties of planets in such systems using for example the upcoming James Webb Space Telescope (JWST), can investigate the differences in formation efficiency and evolution for planetary systems between different Galactic components (thick and thin disks, and halo).
凌日系外行星调查卫星（TESS）已经开始发现附近冷亮恒星周围最终会有数千颗系外行星。这些潜在的宿主恒星必须得到很好的理解，才能在个体和种群水平上准确地描述系外行星。我们使用来自Gaia DR 2，APOGEE，GALAH，RAVE，LAMOST的调查数据和SkyMapper的光度导出的恒星特性，列出了TESS候选目标列表中2，218，434颗恒星的化学运动学特性目录。我们计算了这些恒星的运动学薄盘、厚盘和晕成员概率，发现尽管大多数TESS目标位于薄盘中，但其中4%位于厚盘中，<1%位于晕中。我们样本中的TESS感兴趣对象也显示了来自薄盘、厚盘和晕的类似贡献，其中大部分在薄盘中。我们还探讨了金属丰度和[α/Fe]分布的每个银河系的组成部分，并表明，每个交叉匹配的调查表现出金属丰度和[α/Fe]分布函数，峰值从高到低的金属丰度和低到高的[α/Fe]从薄盘的晕。这个目录将有助于探索行星的出现率，除其他事项外，关于运动学，组件成员，金属丰度，或[阿尔法/铁]。
The TESS-Keck Survey II: An Ultra-Short Period Rocky Planet and its Siblings Transiting the Galactic Thick-Disk Star TOI-561
我们报告了TOI-561的发现，这是一个位于银河系厚盘中的多行星系统，其中包含一颗岩石，超短周期行星（USP）。这颗明亮的恒星（$V=10.2$）拥有三颗小型凌日行星：TOI-561 b（TOI-561.02，P=0.44天，$R_b = 1.45\pm0.11\,R_\oplus$），c（TOI-561.01，P=10.8天，$R_c=2.90\pm0.13\,R_\oplus$）和d（TOI-561.03，P=16.3天，$R_d=2.32\pm0.16\,R_\oplus$）。这颗恒星的化学成分（[Fe/H] $=-0.41\pm0.05$，[ $α$ /H] $=+0.23\pm0.05$）和运动学上与银河系厚盘一致，使TOI-561成为迄今发现的最古老（$10\pm3\,$ Gyr）和最贫金属的行星系统之一。我们动态地确认行星b和c的径向速度从W。M.凯克天文台高分辨率中阶梯光谱仪。行星b的质量和密度为$3.2\pm0.8\,M_\oplus$和$5.5^{+2.0}_{-1.6}\,$ g $\,$ cm $^{-3}$，与岩石组成一致。它的密度低于平均值，与贫铁的组成相一致，尽管不排除类似地球的铁与硅酸盐的比例。行星c是$7.0\pm2.3\,M_\oplus$和$1.6\pm0.6\,$ g $\,$ cm $^{-3}$，与覆盖着低质量挥发性包层的内部岩石核心一致…
Planets Across Space and Time (PAST). VIII : Kinematic Characterization and Identification of Radial Velocity Variables for the LAMOST-Gaia-TESS Stars
School of Astronomy and Space Science, Nanjing University（南京大学天文与空间科学学院）；School of Physics and Astronomy, Sun Yat-sen University（中山大学物理学院）；Institute for Frontiers in Astronomy and Astrophysics, Beijing Normal University（北京师范大学天文与前沿科学研究院）；School of Physics and Astronomy, Beijing Normal University（北京师范大学物理学院）；Department of Astronomy, School of Physics, Peking University（北京大学物理学院天文学系）；Kavli Institute of Astronomy and Astrophysics, Peking University（北京大学科维理天文与天体物理研究所）；National Astronomical Observatories, Chinese Academy of Science（中国科学院国家天文台）
Gas-depleted planet formation occurred in the four-planet system around the red dwarf LHS 1903
Centre for Exoplanet Science, School of Physics and Astronomy, University of St Andrews（圣安德鲁斯大学物理与天文学学院系外行星科学中心）；Department of Physics, University of Warwick（华威大学物理系）；Department of Astronomy and Department of Physics, University of Michigan（密歇根大学天文系和物理系）；Department of Physics & Astronomy, McMaster University（麦克马斯特大学物理与天文学系）；Center for Astrophysics, Harvard & Smithsonian（哈佛史密森尼天体物理中心）；Instituto de Astrofisica e Ciencias do Espaco, Universidade do Porto（波尔图大学太空科学与天体物理研究所）；Departamento de Fisica e Astronomia, Faculdade de Ciencias, Universidade do Porto（波尔图大学理学院物理与天文学系）；Physikalisches Institut, University of Bern（伯尔尼大学物理研究所）；Center for Space and Habitability, University of Bern（伯尔尼大学太空与宜居性中心）；Space sciences, Technologies and Astrophysics Research Institute, Université de Liège（列日大学空间科学、技术与天体物理研究所）；Observatoire Astronomique de l’Université de Genève（日内瓦大学天文台）；Space Research Institute, Austrian Academy of Sciences（奥地利科学院空间研究所）
The T16 Planet Hunt: 10,000 New Planet Candidates from TESS Cycle 1 and the Confirmation of a Hot Jupiter Around TIC 183374187
Princeton University（普林斯顿大学）；University of California Los Angeles（加州大学洛杉矶分校）；Carnegie Science Observatories（卡内基科学天文台）；Universidad de Concepción（康塞普西翁大学）；Carnegie Institution for Science（卡内基科学学会）
Galactic Kinematics and Observed Flare Rates of a Volume-Complete Sample of Mid-to-Late M-dwarfs: Constraints on the History of the Stellar Radiation Environment of Planets Orbiting Low-mass Stars
A compact multi-planet system transiting HIP 29442 (TOI-469) discovered by TESS and ESPRESSO. Radial velocities lead to the detection of transits with low signal-to-noise ratio
