FORMING PLANETESIMALS IN VORTICES

In this work we explore the possibility that large-scale, quasi-two-di mensional vortices on the solar nebula act as trapping regions for dus t particles, We show that large-scale vortices may be naturally genera ted in a differentially rotating solar nebula, and we discuss a simple self-similar solution for the vortex pattern, Numerical simulations o f the transport of dust in the presence of vortices on the nebula indi cate that for a Rossby number less than one the Coriolis force pushes the heavy particles into the cores of anticyclonic (retrograde) vortic es. Here the concentration of dust grains becomes much larger than out side in a few periods of revolution of the disk, The cares of anticycl onic vortices are thus identified as candidate regions for rapid plane tesimal formation. (C) 1996 Academic Press, Inc.