The dynamics of dust in a collapsing protostellar cloud and its possible role in planet formation

First results are presented of a calculation describing the collapse of a rotating 'dusty' protostellar cloud. The dust and gas components are calculated separately, although their interaction (e.g., radiation transport, friction, etc.) is taken into account. In the early stages of the collapse the dust is dynamically unimportant. The evolution of the dust cloud is strongly influenced by dust-dust collisions: rapid sedimentation into an equatorial dust disc is found to take place as a result of accumulative dust-dust collisions and the corresponding grain growth. Treating the dust separately from the gas allows comparison of these results with solar-system cosmochemical measurements and with celestial mechanics information and conclusions may be drawn about the time and place of planet formation in the collapsing cloud. (Auth.)