Spin Dynamics of Extrasolar Giant Planets in Planet-Planet Scattering
Abstract
Planet-planet scattering best explains the eccentricity distribution of extrasolar giant planets, and past literature showed that the orbits of planets evolve due to planet-planet scattering. This work studies the spin evolution of planets in planet-planet scattering in two-planet systems. Spin can evolve dramatically due to spin-orbit coupling made possible by the evolving spin and orbital precession during the planet-planet scattering phase. The main source of torque to planet spin is the stellar torque, and the planet-planet torque contribution is negligible. As a consequence of the evolution of the spin, planets can end up with appreciable obliquities (the angle between a planet's own orbit normal and spin axis), with the obliquity distribution peaking at about 10°, and extending to much larger values.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- October 2021
- DOI:
- 10.3847/1538-4357/ac1a14
- arXiv:
- arXiv:2103.15902
- Bibcode:
- 2021ApJ...920..151H
- Keywords:
-
- Exoplanets;
- Planetary dynamics;
- 498;
- 2173;
- Astrophysics - Earth and Planetary Astrophysics
- E-Print:
- 7 pages, 9 figures