TESS 发现一颗绕振荡晚型次巨星的热土星
摘要
我们报告 TOI-197.01 的发现，这是凌星系外行星巡天卫星（TESS）证认的首颗可对宿主星进行星震学的凌星行星。TOI-197（HIP116158）是一颗明亮（V=8.2 mag）、光谱分类为次巨星的恒星，其以约 430 muHz 的平均频率振荡并显示出清晰的混合模特征。振荡幅度证实相较于 Kepler，TESS 较红波段对振荡影响很小，支持 TESS 两分钟采样观测将产出数千颗类太阳振荡天体的预期。星震学建模稳健确定了宿主星半径（2.943±0.064 Rsun）、质量（1.212±0.074 Msun）与年龄（4.9±1.1 Gyr），并表明其刚起步沿红巨星支上升。结合星震学、凌星建模与视向速度观测，我们表明该行星是一颗“热土星”（9.17±0.33 Rearth），轨道周期约 14.3 天，辐照度 343±24 Fearth，质量适中（60.5±5.7 Mearth），密度 0.431±0.062 gcc。TOI-197.01 的性质显示，在亚土星（4-8 Rearth）中发现的宿主星金属度-行星质量关联不延伸至更大半径，表明亚土星与木星间过渡的行星遵循相对狭窄的密度范围。以约 15% 的密度测量精度，TOI-197.01 是迄今表征最好的土星尺寸行星之一，增加了围绕演化恒星的已知凌星行星数目，并展示了 TESS 利用星震学表征系外行星及其宿主星的能力。
引用
@article{arxiv.1901.01643,
title = {A Hot Saturn Orbiting An Oscillating Late Subgiant Discovered by TESS},
author = {Daniel Huber and William J. Chaplin and Ashley Chontos and Hans Kjeldsen and Joergen Christensen-Dalsgaard and Timothy R. Bedding and Warrick Ball and Rafael Brahm and Nestor Espinoza and Thomas Henning and Andres Jordan and Paula Sarkis and Emil Knudstrup and Simon Albrecht and Frank Grundahl and Mads Fredslund Andersen and Pere L. Palle and Ian Crossfield and Benjamin Fulton and Andrew W. Howard and Howard T. Isaacson and Lauren M. Weiss and Rasmus Handberg and Mikkel N. Lund and Aldo M. Serenelli and Jakob Mosumgaard and Amalie Stokholm and Allyson Bierlya and Lars A. Buchhave and David W. Latham and Samuel N. Quinn and Eric Gaidos and Teruyuki Hirano and George R. Ricker and Roland K. Vanderspek and Sara Seager and Jon M. Jenkins and Joshua N. Winn and H. M. Antia and Thierry Appourchaux and Sarbani Basu and Keaton J. Bell and Othman Benomar and Alfio Bonanno and Derek L. Buzasi and Tiago L. Campante and Z. Celik Orhan and Enrico Corsaro and Margarida S. Cunha and Guy R. Davies and Sebastien Deheuvels and Samuel K. Grunblatt and Amir Hasanzadeh and Maria Pia Di Mauro and Rafael A. Garcia and Patrick Gaulme and Leo Girardi and Joyce A. Guzik and Marc Hon and Chen Jiang and Thomas Kallinger and Steven D. Kawaler and James S. Kuszlewicz and Yveline Lebreton and Tanda Li and Miles Lucas and Mia S. Lundkvist and Stephane Mathis and Savita Mathur and Anwesh Mazumdar and Travis S. Metcalfe and Andrea Miglio and Mario J. Monteiro and Benoit Mosser and Anthony Noll and Benard Nsamba and Andrew W. Mann and Jia Mian Joel Ong and S. Ortel and Filipe Pereira and Pritesh Ranadive and Clara Regulo and Thaise S. Rodrigues and Ian W. Roxburgh and Victor Silva Aguirre and Barry Smalley and Mathew Schofield and Sergio G. Sousa and Keivan G. Stassun and Dennis Stello and Jamie Tayar and Timothy R. White and Kuldeep Verma and Mathieu Vrard and M. Yildiz and David Baker and Michael Bazot and Charles Beichmann and Christoph Bergmann and Lisa Bugnet and Bryson Cale and Roberto Carlino and Scott M. Cartwright and Jessie L. Christiansen and David R. Ciardi and Orlagh Creevey and Jason A. Dittmann and Jose Dias Do Nascimento and Vincent van Eylen and Gabor Furesz and Jonathan Gagne and Peter Gao and Kosmas Gazeas and Frank Giddens and Oliver Hall and Saskia Hekker and Michael J. Ireland and Natasha Latouf and Danny LeBrun and Alan M Levine and William Matzko and Eva Natinsky and Emma Page and Peter Plavchan and Masoud Mansouri-Samani and Sean McCauliff and Susan E Mullally and Brendan Orenstein and Aylin Soto and Martin Paegert and Jennifer L. van Saders and Chloe Schnaible and David R. Soderblom and Robert Szabo and Angelle Tanner and C. G. Tinney and Johanna Teske and Alexandra Thomas and Regner Trampedach and Duncan Wright and Thomas T. Yuan and Farzaneh Zohrabi},
journal= {arXiv preprint arXiv:1901.01643},
year = {2019}
}
备注
12 pages (excluding author list and references), 9 figures, 4 tables, accepted for publication in AJ. An electronic version of Table 3 is available as an ancillary file (sidebar on the right)