Orbital evolution of planetesimals in gaseous disks
Abstract
Planets are formed from collisional growth of small bodies in a protoplanetary disk. Bodies much larger than approximately 1 m are mainly controlled by the gravity of the host star and experience weak gas drag; their orbits are mainly expressed by orbital elements: semimajor axes a, eccentricities e, and inclinations i, which are modulated by gas drag. In a previous study, dot a, dot e, and dot i were analytically derived for e≪1 and i≪H/a, where H is the scale height of the disk. Their formulae are valid in the early stage of planet formation. However, once massive planets are formed, e and i increase greatly. Indeed, some small bodies in the solar system have very large e and i. Therefore, in this paper, I analytically derive formulae for dot a, dot e, and dot i for 1e 2≪1 and i≪H/a and for i≫H/a. The formulae combined from these limited equations will represent the results of orbital integration unless e≥1 or i>πH/a. Since the derived formulae are applicable for bodies not only in a protoplanetary disk but also in a circumplanetary disk, I discuss the possibility of the capture of satellites in a circumplanetary disk using the formulae.
 Publication:

Earth, Planets and Space
 Pub Date:
 April 2015
 DOI:
 10.1186/s406230150218y
 arXiv:
 arXiv:1505.01568
 Bibcode:
 2015EP&S...67...60K
 Keywords:

 Astrophysics  Earth and Planetary Astrophysics
 EPrint:
 accepted for publication in Earth, Planets and Space, 11 pages, 4 figures