热海王星沙漠中的一颗行星残留核
摘要
巨行星的内部结构仍知之甚少。即便对于太阳系内的行星，观测上的困难也导致行星核性质存在很大的不确定性。经历过罕见演化过程的系外行星为理解行星内部提供了一条途径。在典型荒芜的热海王星“沙漠”（质量-半径空间中包含极少行星的区域）内及附近发现的行星在这方面已被证明尤其有价值。这些行星包括被认为具有异常大质量核的 HD149026b，以及最近的发现如 LTT9779b 和 NGTS-4b，其外层大气的大部分已被光致蒸发移除。本文我们报道对行星 TOI-849b 的观测，其半径小于海王星，但具有异常大的质量 地球质量以及 克每立方厘米的密度，与地球相似。内部结构模型表明，任何纯氢氦气体包层至多占总行星质量的 %。该行星在经历热自瓦解或巨行星碰撞导致的极端质量损失之前可能是一颗气态巨行星，或者它可能避免了大量的气体吸积，或许是通过缝隙打开或晚期形成。尽管光致蒸发速率无法解释将类木气态巨行星缩减所需的质量损失，但它们能在数十亿年的时间尺度上移除一个小（几地球质量）的氢氦包层，这意味着 TOI-849b 上任何残留大气都可能被来自行星内部的水或其他挥发性物质所富集。我们得出结论：TOI-849b 是一颗巨行星的残留核。
引用
@article{arxiv.2003.10314,
title = {A remnant planetary core in the hot-Neptune desert},
author = {David J. Armstrong and Théo A. Lopez and Vardan Adibekyan and Richard A. Booth and Edward M. Bryant and Karen A. Collins and Alexandre Emsenhuber and Chelsea X. Huang and George W. King and Jorge Lillo-box and Jack J. Lissauer and Elisabeth C. Matthews and Olivier Mousis and Louise D. Nielsen and Hugh Osborn and Jon Otegi and Nuno C. Santos and Sérgio G. Sousa and Keivan G. Stassun and Dimitri Veras and Carl Ziegler and Jack S. Acton and Jose M. Almenara and David R. Anderson and David Barrado and Susana C. C. Barros and Daniel Bayliss and Claudia Belardi and Francois Bouchy and César Briceno and Matteo Brogi and David J. A. Brown and Matthew R. Burleigh and Sarah L. Casewell and Alexander Chaushev and David R. Ciardi and Kevin I. Collins and Knicole D. Colón and Benjamin F. Cooke and Ian J. M. Crossfield and Rodrigo F. Díaz and Magali Deleuil and Elisa Delgado Mena and Olivier D. S. Demangeon and Caroline Dorn and Xavier Dumusque and Philipp Eigmuller and Michael Fausnaugh and Pedro Figueira and Tianjun Gan and Siddharth Gandhi and Samuel Gill and Michael R. Goad and Maximilian N. Guenther and Ravit Helled and Saeed Hojjatpanah and Steve B. Howell and James Jackman and James S. Jenkins and Jon M. Jenkins and Eric L. N. Jensen and Grant M. Kennedy and David W. Latham and Nicholas Law and Monika Lendl and Michael Lozovsky and Andrew W. Mann and Maximiliano Moyano and James McCormac and Farzana Meru and Christoph Mordasini and Ares Osborn and Don Pollacco and Didier Queloz and Liam Raynard and George R. Ricker and Pamela Rowden and Alexandre Santerne and Joshua E. Schlieder and S. Seager and Lizhou Sha and Thiam-Guan Tan and Rosanna H. Tilbrook and Eric Ting and Stéphane Udry and Roland Vanderspek and Christopher A. Watson and Richard G. West and Paul A. Wilson and Joshua N. Winn and Peter Wheatley and Jesus Noel Villasenor and Jose I. Vines and Zhuchang Zhan},
journal= {arXiv preprint arXiv:2003.10314},
year = {2020}
}
备注
Published in Nature. This is a preprint of the article, before minor changes made during the refereeing and editing process. The published PDF is at https://www.nature.com/articles/s41586-020-2421-7 and can be accessed for free by following this link: https://rdcu.be/b5miB . Abstract updated to match published version