Open AccessThe evolution of eccentric protoplanetary orbits
Author(s) -
Woolfson M. M.
Publication year - 2003
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.2003.06187.x
Subject(s) - physics , protoplanet , exoplanet , planet , circular orbit , astronomy , classical mechanics , eccentricity (behavior) , orbit (dynamics) , astrophysics , gravitation , planetary system , protoplanetary disk , engineering , political science , law , aerospace engineering
The migration of planets has usually been considered in relation to circular orbits of protoplanets for which type I and II migration mechanisms are appropriate. There are theories for planetary origin in which protoplanets are produced in extended eccentric orbits requiring a different theoretical treatment. The basic mechanism for the action of a resisting medium involves gravitational interaction with the planet and the simple application of the principle of conservation of momentum. A gaseous resisting medium will be in the form of a flared disc with a three‐dimensional structure. Such a medium is simulated by a distribution of non‐interacting particles, initially in a stable orbit around the central star. Their gravitational interactions with the protoplanet are softened, as for particles in smoothed‐particle hydrodynamics, to avoid gravitational singularities. Computations, in which parameters are varied in a systematic manner, give a range of final orbits similar to those observed and inferred for exoplanets. When the motion of the medium is affected by high luminosity and/or a strong stellar wind from an active young star, orbits of high eccentricity may be an outcome, as is observed for some exoplanets.