Runaway planetary growth with collision rate in the solar gravitational field

The present examination of the effects of collision rates among solar gravitational field planetesimals on runaway planetary growth qualitatively explains the orbital calculations of Ida and Nakazawa (1989) in view of a two-body approximation which neglects the sun. The competitive growth of several protoplanets is numerically simulated with a simple model. The results obtained show that the collision rate in the solar gravitational field enhances the possibility of runaway growth in a certain low-velocity region, in contrast to the two-body approximation. 19 refs