Stellar systems consisting of multiple stars tend to undergo tidal interactions when the separations between the stars are short. While tidal phenomena have been extensively studied, a certain tidal effect exclusive to hierarchical triples (triples in which one component star has a much wider orbit than the others) has hardly received any attention, mainly due to its complexity and consequent resistance to being modelled. This tidal effect is the tidal perturbation of the tertiary by the inner binary, which in turn depletes orbital energy from the inner binary, causing the inner binary separation to shrink. In this paper, we develop a fully numerical simulation of these "tertiary tides" by modifying established tidal models. We also provide general insight as to how close a hierarchical triple needs to be in order for such an effect to take place, and demonstrate that our simulations can effectively retrieve the orbital evolution for such systems. We conclude that tertiary tides are a significant factor in the evolution of close hierarchical triples, and strongly influence at least ~ 1% of all multiple star systems.
Competition between gravity waves excited by convection and tides in stars that host a companion
KU Leuven（荷语鲁汶大学）；CEA（法国原子能和替代能源委员会）；Observatoire de Genève, Université de Genève（日内瓦大学天文台）；Université Paris-Saclay, Université Paris Cité, CEA, CNRS, AIM（巴黎萨克雷大学、巴黎西岱大学、法国原子能和替代能源委员会、法国国家科学研究中心、天体物理信息与测量实验室）；Instituut voor Sterrenkunde, KU Leuven（荷语鲁汶大学天文研究所）
Planet Hunters TESS IV: A massive, compact hierarchical triple star system TIC 470710327
我们报告了一个大规模的，紧凑的，分层的三重系统（TIC 470710327）的发现和分析，最初由公民科学家在美国宇航局的凌日系外行星调查卫星（TESS）获得的数据中确定。用HERMES摄谱仪获得的光谱跟踪观测，结合日食定时变化（ETVs），证实该系统由三颗OB星组成，其中一颗是紧凑的1.10 d食双星，另一颗是在52.04 d轨道上的非食三级星。该系统的动力学模型（来自径向速度和ETVs）揭示了一种罕见的配置，其中第三恒星（O9.5-B0.5V; 14-17 M $_{\odot}$）的质量比内部双星（10.9-13.2 M $_{\odot}$）的质量更大。考虑到第三纪的高质量，我们预测这个系统在未来将经历多个阶段的质量转移，并可能最终成为双中子星引力波的祖先或一个异国情调的索恩-Zytkow对象。进一步的观测特性，这个系统的承诺约束的大质量恒星的形成方案，以及他们的异国情调的进化的最终产品。
Temperature and Distance Dependence of Tidal Circularization in Close Binaries: A Catalog of Eclipsing Binaries in the Southern Hemisphere Observed by the TESS Satellite
Coralie radial-velocity search for companions around evolved stars (CASCADES) III. A new Jupiter host-star: in-depth analysis of HD 29399 using TESS data
