K2-146周围需两颗行星共振共舞
地球与行星天体物理
2020-03-04 v1
摘要
K2-146是一颗冷的0.358 M_sun矮星，被发现拥有一颗周期为2.67天的迷你海王星。该行星表现出大于30分钟的强凌星计时变化（TTV），表明系统中存在另一天体。本文利用额外的测光数据报道了系统中此前未探测到的外行星K2-146 c的发现。K2-146 c被发现有掠凌几何形态及3.97天的周期。该外行星仅在后期的K2观测活动中被显著探测到，推测是由于其轨道平面进动所致。利用跨度近1200天的观测测量了K2-146 b和c的TTV。我们发现TTV之间存在强反相关，表明两颗行星存在引力相互作用。我们的TTV与凌星模型分析揭示，K2-146 b半径为2.25 ± 0.10 R_earth、质量为5.6 ± 0.7 M_earth，而K2-146 c半径为 R_earth、质量为7.1 ± 0.9 M_earth。内、外行星可能具有中等偏心率，分别为和。对两行星轨道解的长期数值积分表明其动力学上至少稳定2 Myr。对该行星对共振角的评估表明，K2-146 b和c很可能被困在3:2平运动共振中。该系统的轨道架构指向一种可能的收敛迁移起源。
引用
@article{arxiv.1907.11141,
title = {It takes two planets in resonance to tango around K2-146},
author = {Kristine W. F. Lam and Judith Korth and Kento Masuda and Szilárd Csizmadia and Philipp Eigmüller and Guðmundur Kári Stefánsson and Michael Endl and Simon Albrecht and Rafael Luque and John H. Livingston and Teruyuki Hirano and Roi Alonso Sobrino and Oscar Barragán and Juan Cabrera and Ilaria Carleo and Alexander Chaushev and William D. Cochran and Fei Dai and Jerome de Leon and Hans J. Deeg and Anders Erikson and Massimiliano Esposito and Malcolm Fridlund and Akihiko Fukui and Davide Gandolfi and Iskra Georgieva and Lucá Gonzalez Cuesta and Sascha Grziwa and Eike W. Guenther and Artie P. Hatzes and Diego Hidalgo and Maria Hjorth and Petr Kabath and Emil Knudstrup and Mikkel N. Lund and Suvrath Mahadevan and Savita Mathur and Pilar Montañes Rodríguez and Felipe Murgas and Norio Narita and David Nespral and Prajwal Niraula and Enric Palle and Martin Pätzold and Carina M. Persson and Jorge Prieto-Arranz and Heike Rauer and Seth Redfield and Ignasi Ribas and Paul Robertson and Marek Skarka and Alexis M. S. Smith and Jan Subjak and Vincent Van Eylen},
journal= {arXiv preprint arXiv:1907.11141},
year = {2020}
}
备注
19 pages with 13 figures and 4 tables; Submitted