多行星系统 TOI-421——一颗温暖的海王星与一颗超蓬松迷你海王星凌食视觉双星中的 G9 V 恒星
地球与行星天体物理
2021-01-18 v3 太阳与恒星天体物理
摘要
我们报告发现一颗温暖的海王星和一颗热亚海王星凌食 TOI-421（BD-14 1137，TIC 94986319），这是一颗由 TESS 空间任务在第 5 和第 6 扇区观测到的明亮（V=9.9）G9 矮星，位于视觉双星系统中。我们进行了地基后续观测——包括 LCOGT 凌食测光、NIRC2 自适应光学成像，以及 FIES、CORALIE、HARPS、HIRES 和 PFS 高精度多普勒测量——并确认了 TESS 团队宣布的 16 天凌食候选体的行星性质。我们发现由系统中第二颗行星引起的额外径向速度信号，周期为 5 天，我们也发现它凌食其宿主恒星。我们发现内侧迷你海王星 TOI-421b 的轨道周期为 Pb = 5.19672 ± 0.00049 天，质量为 Mb = 7.17 ± 0.66 Mearth，半径为 Rb = 2.68+0.19-0.18 Rearth，而外侧温暖海王星 TOI-421c 的周期为 Pc = 16.06819 ± 0.00035 天，质量为 Mc = 16.42+1.06-1.04 Mearth，半径为 Rc = 5.09+0.16-0.15 Rearth，密度为 rho_c = 0.685+0.080-0.072 g cm-3。根据其特性，内侧行星（rho_b = 2.05+0.52-0.41 g cm-3）被归入引人关注的超蓬松迷你海王星一类。TOI-421b 和 TOI-421c 被发现非常适合大气表征。我们的大气模拟预测显著的 Ly-alpha 凌食吸收，源于两颗行星中强烈的氢逃逸，以及若假设平衡化学则在 TOI-421c 大气中存在可探测的 CH_4。
引用
@article{arxiv.2004.10095,
title = {The multi-planet system TOI-421 -- A warm Neptune and a super puffy mini-Neptune transiting a G9 V star in a visual binary},
author = {Ilaria Carleo and Davide Gandolfi and Oscar Barragán and John H. Livingston and Carina M. Persson and Kristine W. F. Lam and Aline Vidotto and Michael B. Lund and Carolina Villarreal D'Angelo and Karen A. Collins and Luca Fossati and Andrew W. Howard and Daria Kubyshkina and Rafael Brahm and Antonija Oklopčić and Paul Mollière and Seth Redfield and Luisa Maria Serrano and Fei Dai and Malcolm Fridlund and Francesco Borsa and Judith Korth and Massimiliano Esposito and Matías R. Díaz and Louise Dyregaard Nielsen and Coel Hellier and Savita Mathur and Hans J. Deeg and Artie P. Hatzes and Serena Benatti and Florian Rodler and Javier Alarcon and Lorenzo Spina and Ângela R. G. Santos and Iskra Georgieva and Rafael A. García and Lucía González-Cuesta and George R. Ricker and Roland Vanderspek and David W. Latham and Sara Seager and Joshua N. Winn and Jon M. Jenkins and Simon Albrecht and Natalie M. Batalha and Corey Beard and Patricia T. Boyd and François Bouchy and Jennifer A. Burt and R. Paul Butler and Juan Cabrera and Ashley Chontos and David Ciardi and William D. Cochran and Kevin I. Collins and Jeffrey D. Crane and Ian Crossfield and Szilard Csizmadia and Diana Dragomir and Courtney Dressing and Philipp Eigmüller and Michael Endl and Anders Erikson and Nestor Espinoza and Michael Fausnaugh and Fabo Feng and Erin Flowers and Benjamin Fulton and Erica J. Gonzales and Nolan Grieves and Sascha Grziwa and Eike W. Guenther and Natalia M. Guerrero and Thomas Henning and Diego Hidalgo and Teruyuki Hirano and Maria Hjorth and Daniel Huber and Howard Isaacson and Matias Jones and Andrés Jordán and Petr Kabáth and Stephen R. Kane and Emil Knudstrup and Jack Lubin and Rafael Luque and Ismael Mireles and Norio Narita and David Nespral and Prajwal Niraula and Grzegorz Nowak and Enric Palle and Martin Pätzold and Erik A Petigura and Jorge Prieto-Arranz and Heike Rauer and Paul Robertson and Mark E. Rose and Arpita Roy and Paula Sarkis and Joshua E. Schlieder and Damien Ségransan and Stephen Shectman and Marek Skarka and Alexis M. S. Smith and Jeffrey C. Smith and Keivan Stassun and Johanna Teske and Joseph D. Twicken and Vincent Van Eylen and Sharon Wang and Lauren M. Weiss and Aurélien Wyttenbach},
journal= {arXiv preprint arXiv:2004.10095},
year = {2021}
}