论文标题
热木星系统中的轨道时期调制
Orbital period modulation in hot Jupiter systems
论文作者
论文摘要
我们基于旋转轨道耦合的巨型行星的系统中引入了一个模型，该模型将角动量从轨道转移到行星和Viceversa的旋转。耦合是由假定存在于行星固体芯中的永久性非轴对称引力四极矩产生的。我们研究了内部行星旋转的两个机制，即，当行星刚性旋转时，当它的深内部旋转时，由于其外壳中的摇摆不定或间歇对流，其深内部的旋转是依赖时间的。该模型应用于非常热的木星样品，可预测在刚性旋转的情况下，恒定周期胚胎的最大转运时间偏差约为50秒。 WASP-12的运输时间变化，目前是唯一显示出非恒定周期证据的系统，无法通过假设刚性旋转来解释，但可以在时间依赖性的内部旋转方向上进行建模，从而为他们的解释提供了一种替代行星腐烂的解释。
We introduce a model for the orbital period modulation in systems with close-by giant planets based on a spin-orbit coupling that transfers angular momentum from the orbit to the rotation of the planet and viceversa. The coupling is produced by a permanent non-axisymmetric gravitational quadrupole moment assumed to be present in the solid core of the planet. We investigate two regimes of internal planetary rotation, that is, when the planet rotates rigidly and when the rotation of its deep interior is time dependent as a consequence of a vacillating or intermittent convection in its outer shell. The model is applied to a sample of very hot Jupiters predicting maximum transit-time deviations from a constant-period ephemeris of approximately 50 seconds in the case of rigid rotation. The transit time variations of WASP-12, currently the only system showing evidence of a non-constant period, cannot be explained by assuming rigid rotation, but can be modelled in the time-dependent internal rotation regime, thus providing an alternative to their interpretation in terms of a tidal decay of the planet orbit.
