Abstract
We study the formation of a giant gas planet by the core-accretion gas-capture process, with numerical simulations, under the assumption that the planetary core forms in the center of an anti-cyclonic vortex. The presence of the vortex concentrates particles of centimeter to meter size from the surrounding disk, and speeds up the core formation process. Assuming that a planet of Jupiter mass is forming at 5 AU from the star, the vortex enhancement results in considerably shorter formation times than are found in standard core-accretion gas-capture simulations. Also, formation of a gas giant is possible in a disk with mass comparable to that of the minimum mass solar nebula (MMSN).