论文标题
冥王星二元的潮汐演变
Tidal evolution of the Pluto-Charon binary
论文作者
论文摘要
据信巨大的碰撞是冥王星夏隆系统的起源。结果，撞击后的初始轨道和旋转可能与今天观察到的轨道有很大不同。更确切地说，佩里亚普（Periapse）的距离可能较短，随后通过同时在两个物体上同时升高的潮汐扩展到其当前的分离。在这里，我们提供了一个一般的3D模型，以研究由绕中央恒星绕的两个三轴体组成的二元的潮汐演化。我们将此模型应用于冥王星 - 夏隆二进制，并在初始系统上注意一些有趣的约束。我们观察到，当偏心率演变成高价值时，由于利多夫 - 科泽（Lidov-Kozai）周期，太阳的存在阻止了夏隆逃脱。但是，对于冥王星的高初始斜率或旋转轨道旋转的旋转轨道捕获，二进制偏心率非常有效地减弱。结果，即使对于冥王星上的强烈潮汐耗散，系统也可以保持中等的偏心率。
A giant collision is believed to be at the origin of the Pluto-Charon system. As a result, the initial orbit and spins after impact may have substantially differed from those observed today. More precisely, the distance at periapse may have been shorter, subsequently expanding to its current separation by tides raised simultaneously on the two bodies. Here we provide a general 3D model to study the tidal evolution of a binary composed of two triaxial bodies orbiting a central star. We apply this model to the Pluto-Charon binary, and notice some interesting constraints on the initial system. We observe that when the eccentricity evolves to high values, the presence of the Sun prevents Charon from escaping because of Lidov-Kozai cycles. However, for a high initial obliquity for Pluto or a spin-orbit capture of Charon's rotation, the binary eccentricity is damped very efficiently. As a result, the system can maintain a moderate eccentricity throughout its evolution, even for strong tidal dissipation on Pluto.
