海王星沙漠中的一颗超热海王星
地球与行星天体物理
2020-09-30 v2 太阳与恒星天体物理
摘要
约每 200 颗类太阳恒星中就有 1 颗拥有轨道周期短于一天的行星：超短周期行星（Sanchis-ojeda et al. 2014; Winn et al. 2018）。所有此前已知的超短周期行星要么是热木星（半径大于 10 个地球半径 ），要么是小于 2 的表观岩质行星。这种中等大小行星的缺失（即“热海王星沙漠”）被解释为低质量行星在强恒星辐照下无法保留任何氢/氦（H/He）包层。在此，我们报告发现一颗超短周期行星，其半径为 4.6 、质量为 29 ，正位于热海王星沙漠之中。来自凌星系外行星巡天卫星（Ricker et al. 2015）的数据揭示了明亮类太阳恒星 \starname\ 每 0.79 天的凌星现象。该行星的平均密度与海王星相似，且根据热演化模型，其 H/He 富包层占总质量的 9.0^(+2.7)_(-2.9)%。其平衡温度约 2000 K，目前尚不清楚这颗“超热海王星”如何保留了这样的包层。该恒星亮度高（Vmag=9.8），将有助于对行星大气开展后续观测，以更好地理解其起源与物理本质。
引用
@article{arxiv.2009.12832,
title = {An Ultra-Hot Neptune in the Neptune desert},
author = {James S. Jenkins and Matías R. Díaz and Nicolás T. Kurtovic and Néstor Espinoza and Jose I. Vines and Pablo A. Peña Rojas and Rafael Brahm and Pascal Torres and Pía Cortés-Zuleta and Maritza G. Soto and Eric D. Lopez and George W. King and Peter J. Wheatley and Joshua N. Winn and David R. Ciardi and George Ricker and Roland Vanderspek and David W. Latham and Sara Seager and Jon M. Jenkins and Charles A. Beichman and Allyson Bieryla and Christopher J. Burke and Jessie L. Christiansen and Christopher E. Henze and Todd C. Klaus and Sean McCauliff and Mayuko Mori and Norio Narita and Taku Nishiumi and Motohide Tamura and Jerome Pitogo de Leon and Samuel N. Quinn and Jesus Noel Villaseñor and Michael Vezie and Jack J. Lissauer and Karen A. Collins and Kevin I. Collins and Giovanni Isopi and Franco Mallia and Andrea Ercolino and Cristobal Petrovich and Andrés Jordán and Jack S. Acton and David J. Armstrong and Daniel Bayliss and François Bouchy and Claudia Belardi and Edward M. Bryant and Matthew R. Burleigh and Juan Cabrera and Sarah L. Casewell and Alexander Chaushev and Benjamin F. Cooke and Philipp Eigmüller and Anders Erikson and Emma Foxell and Boris T. Gänsicke and Samuel Gill and Edward Gillen and Maximilian N. Günther and Michael R. Goad and Matthew J. Hooton and James A. G. Jackman and Tom Louden and James McCormac and Maximiliano Moyano and Louise D. Nielsen and Don Pollacco and Didier Queloz and Heike Rauer and Liam Raynard and Alexis M. S. Smith and Rosanna H. Tilbrook and Ruth Titz-Weider and Oliver Turner and Stéphane Udry and Simon. R. Walker and Christopher A. Watson and Richard G. West and Enric Palle and Carl Ziegler and Nicholas Law and Andrew W. Mann},
journal= {arXiv preprint arXiv:2009.12832},
year = {2020}
}
备注
26 pages, 10 figures, 3 tables. Published in Nature Astronomy (21/09/2020)