使用CHEOPS、TESS及归档径向速度数据对TOI-421星系进行表征
地球与行星天体物理
2024-04-18 v1
摘要
TOI-421星系包含两颗亚海德星型行星，是研究行星形成与演化及其大气的理想目标。其中一颗行星尤为有趣，其在轨道分离处存在氢化合物大气，此现象若无以前的轨道迁移，当前形成模型无法解释。我们联合分析了三个TESS星区和六次CHEOPS访问的光度数据，以及156个径向速度数据点，以获取改进的行星参数。我们还搜索了TTV信号并对行星内部结构进行建模。最终，我们使用两种不同的建模框架模拟行星原始H-He大气的演化。我们确定TOI-421 b和c的行星半径和质量分别为，，，。我们未检测到任何统计显著的TTV信号。假设存在氢化合物大气，内部结构建模表明两颗行星都拥有广泛的包裹层。虽然大气演化模型预测TOI-421 b将在其当前轨道位置失去任何原始大气，但TOI-421 c可能最初拥有10%至35%的大气质量分数。我们得出结论，TOI-421 b观察到的低平均密度只能通过两种方式解释：要么测量的行星参数存在偏差（例如由高空云层驱动），要么在轨道迁移的情境下。我们还发现大气演化模型的结果在所采用的行星结构模型上具有强烈依赖性。
引用
@article{arxiv.2404.11074,
title = {Characterisation of the TOI-421 planetary system using CHEOPS, TESS, and archival radial velocity data},
author = {A. F. Krenn and D. Kubyshkina and L. Fossati and J. A. Egger and A. Bonfanti and A. Deline and D. Ehrenreich and M. Beck and W. Benz and J. Cabrera and T. G. Wilson and A. Leleu and S. G. Sousa and V. Adibekyan and A. C. M. Correira and Y. Alibert and L. Delrez and M. Lendl and J. A. Patel and J. Venturini and R. Alonso and G. Anglada and J. Asquier and T. Bárczy and D. Barrado Navascues and S. C. C. Barros and W. Baumjohann and T. Beck and N. Billot and X. Bonfils and L. Borsato and A. Brandeker and C. Broeg and S. Charnoz and A. Collier Cameron and Sz. Csizmadia and P. E. Cubillos and M. B. Davies and M. Deleuil and O. D. S. Demangeon and B. -O. Demory and A. Erikson and A. Fortier and M. Fridlund and D. Gandolfi and M. Gillon and M. Güdel and M. N. Günther and J. Hasiba and A. Heitzmann and C. Helling and S. Hoyer and K. G. Isaak and L. L. Kiss and K. W. F. Lam and J. Laskar and A. Lecavelier des Etangs and C. Lovis and D. Magrin and P. F. L. Maxted and C. Mordasini and V. Nascimbeni and G. Olofsson and R. Ottensamer and I. Pagano and E. Pallé and G. Peter and G. Piotto and D. Pollacco and D. Queloz and R. Ragazzoni and N. Rando and H. Rauer and I. Ribas and M. Rieder and N. C. Santos and G. Scandariato and D. Ségransan and A. E. Simon and A. M. S. Smith and M. Stalport and M. Steller and Gy. M. Szabó and N. Thomas and S. Udry and B. Ulmer and V. Van Grootel and E. Villaver and V. Viotto and N. A. Walton and T. Zingales},
journal= {arXiv preprint arXiv:2404.11074},
year = {2024}
}
备注
21 pages, 12 figures, accepted for publication in A&A