论文标题
科伦坡顶部的动力：从行星盘相互作用产生系外行星倾斜
Dynamics of Colombo's Top: Generating Exoplanet Obliquities from Planet-Disk Interactions
论文作者
论文摘要
大的行星旋转轨道未对准（倾斜）可能会强烈影响地球上的大气循环和潮汐加热。一种有希望的途径产生倾斜的是通过自旋轨道共振，随着系统的及时演变，行星的旋转和轨道进动频率相互交叉。一种这样的机制涉及驱动内部行星轨道进动的耗散（质量失去的）原球磁盘。我们在本文中分析研究了这种情况，并在一般初始旋转方向和最终倾斜之间获得映射。我们表明（i）在绝热的演化下（即磁盘以足够缓慢的速度消散），最终的行星倾斜作为初始旋转方向的函数，分叉成由与共振相互作用的不同轨道； （ii）在非绝热进化下，可以激发广泛的倾斜范围。我们获得了各种参数空间状态的最终斜率的分析表达式。本文研究的动态系统是“科伦坡顶部”的一个示例，我们的分析和结果可以适应其他应用程序。
Large planetary spin-orbit misalignments (obliquities) may strongly influence atmospheric circulation and tidal heating in the planet. A promising avenue to generate obliquities is via spin-orbit resonances, where the spin and orbital precession frequencies of the planet cross each other as the system evolves in time. One such mechanism involves a dissipating (mass-losing) protoplanetary disk that drives orbital precession of an interior planet. We study this scenario analytically in this paper, and obtain the mapping between the general initial spin orientation and the final obliquity. We show that (i) under adiabatic evolution (i.e. the disk dissipates at a sufficiently slow rate), the final planetary obliquity as a function of the initial spin orientation bifurcates into distinct tracks governed by interactions with the resonance; (ii) under nonadiabatic evolution, a broad range of obliquities can be excited. We obtain analytical expressions for the final obliquities for various regimes of parameter space. The dynamical system studied in this paper is an example of "Colombo's top", and our analysis and results can be adapted to other applications.
