The great escape: how exoplanets and smaller bodies desert dying stars
Abstract
Mounting discoveries of extrasolar planets orbiting post-main-sequence stars motivate studies to understand the fate of these planets. In the traditional 'adiabatic' approximation, a secondary's eccentricity remains constant during stellar mass-loss. Here, we remove this approximation, investigate the full two-body point-mass problem with isotropic mass-loss, and illustrate the resulting dynamical evolution. The magnitude and duration of a star's mass-loss combined with a secondary's initial orbital characteristics might provoke ejection, modest eccentricity pumping, or even circularization of the orbit. We conclude that Oort Clouds and wide-separation planets may be dynamically ejected from 1-7 M⊙ parent stars during AGB evolution. The vast majority of planetary material that survives a supernova from a 7-20 M⊙ progenitor will be dynamically ejected from the system, placing limits on the existence of first-generation pulsar planets. Planets around >20 M⊙ black hole progenitors may easily survive or readily be ejected depending on the core collapse and superwind models applied. Material ejected during stellar evolution might contribute significantly to the free-floating planetary population.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- November 2011
- DOI:
- 10.1111/j.1365-2966.2011.19393.x
- arXiv:
- arXiv:1107.1239
- Bibcode:
- 2011MNRAS.417.2104V
- Keywords:
-
- Oort Cloud;
- planets and satellites: dynamical evolution and stability;
- planet-star interactions;
- stars: AGB and post-AGB;
- stars: evolution;
- supernovae: general;
- Astrophysics - Earth and Planetary Astrophysics;
- Astrophysics - Solar and Stellar Astrophysics;
- Physics - Classical Physics
- E-Print:
- 23 pages, 16 figures, accepted for publication in MNRAS