On the Fate of Unstable Circumbinary Planets: Tatooine’s Close Encounters with a Death Star
Abstract
Circumbinary planets whose orbits become unstable may be ejected, accreted, or even captured by one of the stars. We quantify the relative rates of these channels, for a binary of secondary star’s mass fraction 0.1 with an orbit of 1 AU. The most common outcome is ejection, which happens ∼80% of the time. If binary systems form circumbinary planets readily and sloppily, this process may fill the Milky Way with free-floating planets. A significant fraction of the time, ∼20%, the unstable planet strikes the primary or secondary. We tracked whether a Jupiter-like planet would undergo tidal stripping events during close passages, and find that these events are rarely strong enough to capture the planet, although this may be observable via free-floating planets that are heated or spun-up by this process.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- February 2016
- DOI:
- 10.3847/0004-637X/818/1/6
- arXiv:
- arXiv:1511.03274
- Bibcode:
- 2016ApJ...818....6S
- Keywords:
-
- planetary systems;
- planets and satellites: detection;
- planets and satellites: dynamical evolution and stability;
- Astrophysics - Earth and Planetary Astrophysics
- E-Print:
- 7 pages, 7 figures. ApJ reviewed, awaiting resubmission