KELT-18b：膨胀行星，炽热宿主，可能受扰动
地球与行星天体物理
2017-05-31 v2
摘要
我们报告发现KELT-18b，一颗凌星热木星，轨道周期2.87天，围绕明亮(V=10.1)、炽热的F4V恒星BD+60 1538 (TYC 3865-1173-1)。我们呈现了后续测光、光谱和自适应光学成像，从而能够详细描述该系统。我们的首选模型拟合给出宿主恒星温度6670±120 K，质量1.524±0.069 M_sun，使其成为已知少数拥有如此炽热、大质量且明亮宿主恒星的凌星行星之一。该行星质量1.18±0.11 M_jup，半径1.57±0.04 R_jup，密度0.377±0.040 g/cm^3，使其成为已知围绕热恒星的最膨胀行星之一。我们认为KELT-18b的高温和低表面重力（估计大气标高约600 km），加上其炽热明亮的宿主，使其成为大气表征观测的极佳候选。我们还展示了在投影距离约1100 AU处存在一个束缚恒星伴星的证据，并推测它可能导致了我们怀疑的KELT-18自转轴与其行星轨道轴之间的强烈错位。下合时刻为2457542.524998 ±0.000416 (BJD_TDB)，轨道周期为2.8717510 ± 0.0000029天。我们鼓励近期进行Rossiter-McLaughlin测量以确认该系统的自旋-轨道错位。
引用
@article{arxiv.1702.01657,
title = {KELT-18b: Puffy Planet, Hot Host, Probably Perturbed},
author = {Kim K. McLeod and Joseph E. Rodriguez and Ryan J. Oelkers and Karen A. Collins and Allyson Bieryla and Benjamin J. Fulton and Keivan G. Stassun and B. Scott Gaudi and Kaloyan Penev and Daniel J. Stevens and Knicole D. Colón and Joshua Pepper and Norio Narita and Ryu Tsuguru and Akihiko Fukui and Phillip A. Reed and Bethany Tirrell and Tiffany Visgaitis and John F. Kielkopf and David H. Cohen and Eric L. N. Jensen and Joao Gregorio and Özgür Baştürk and Thomas E. Oberst and Casey Melton and Eliza M. -R. Kempton and Andrew Baldridge and Y. Sunny Zhao and Roberto Zambelli and David W. Latham and Gilbert A. Esquerdo and Perry Berlind and Michael L. Calkins and Andrew W. Howard and Howard Isaacson and Lauren M. Weiss and Thomas G. Beatty and Jason D. Eastman and Matthew T. Penny and Robert J. Siverd and Michael B. Lund and Jonathan Labadie-Bartz and G. Zhou and Ivan A. Curtis and Michael D. Joner and Mark Manner and Howard Relles and Gaetano Scarpetta and Denise C. Stephens and Chris Stockdale and T. G. Tan and D. L. DePoy and Jennifer L. Marshall and Richard W. Pogge and Mark Trueblood and Patricia Trueblood},
journal= {arXiv preprint arXiv:1702.01657},
year = {2017}
}
备注
16 pages, 13 figures, 6 tables, accepted to AJ