Perturbed Planet Formation: Accounting for Massive Companions in Simulations of Plan- Etesimal Growth

The standard model of planet formation was initially developed to help explain how planets could have formed around our isolated sun. This model typically begins with a protoplanetary disk of gas and dust orbiting a young protostar. Growth of terrestrial planets in such a disk is usually treated in three stages: [stage I] accretion of dust particles into 10 to 10 gram (kilometer-size) planetesimals in ∼10 years, [stage II] gravitational accumulation of planetesimals through a process known as “runaway growth,” which produces 10 to 10 g (Mercuryto Mars-size) planetary embryos in ∼10 years, and [stage III] giant impacts between embryos, resulting in full-size 10 to 10 g terrestrial planets in ∼10-10 years.