Letter to the Editor

Migration and giant planet formation

Physikalisches Insitut, University of Bern, Sidlerstrasse 5, 3012 Bern, Switzerland

Corresponding author: Y. Alibert, yann.alibert@phim.unibe.ch

Received: 19 December 2003
Accepted: 10 February 2004

Abstract

We extend the core-accretion model of giant gaseous planets by Pollack et al. ([CITE]) to include migration, disc evolution and gap formation. Starting with a core of a fraction of an Earth's mass located at 8 AU, we end our simulation with the onset of runaway gas accretion when the planet is at 5.5 AU 1 Myr later. This timescale is about a factor ten shorter than the one found by Pollack et al. ([CITE]) even though the disc was less massive initially and viscously evolving. Other initial conditions can lead to even shorter timescales. The reason for this speed-up is found to result from the fact that a moving planet does not deplete its feeding zone to the extend of a static planet. Thus, the uncomfortably long formation timescale associated with the core-accretion scenario can be considerably reduced and brought in much better agreement with the typical disc lifetimes inferred from observations of young circumstellar discs.