Making Planet Nine: Pebble Accretion at 250-750 AU in a Gravitationally Unstable Ring
Abstract
We investigate the formation of icy super-Earth mass planets within a gravitationally unstable ring of solids orbiting at 250-750 AU around a 1 {M}⊙ star. Coagulation calculations demonstrate that a system of a few large oligarchs and a swarm of pebbles generates a super-Earth within 100-200 Myr at 250 AU and within 1-2 Gyr at 750 AU. Systems with more than ten oligarchs fail to yield super-Earths over the age of the solar system. As these systems evolve, destructive collisions produce detectable debris disks with luminosities of {10}-5{--}{10}-3 relative to the central star.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- July 2016
- DOI:
- 10.3847/0004-637X/825/1/33
- arXiv:
- arXiv:1603.08008
- Bibcode:
- 2016ApJ...825...33K
- Keywords:
-
- planetary systems;
- planets and satellites: formation;
- planets and satellites: individual: Planet Nine;
- planets and satellites: physical evolution;
- Astrophysics - Earth and Planetary Astrophysics;
- Astrophysics - Solar and Stellar Astrophysics
- E-Print:
- 24 pages of text, 1 table, 8 figures, ApJ submitted, comments welcome