Dynamics of Discs and Planets

Ever since the discovery in 1995 of an object with half the mass of Jupiter in a four-day orbit around the star 51 Pegasi, it has been clear that the dynamics of extrasolar planetary systems can be quite different from that of our solar system. More than 200 extrasolar planets have now been found, including at least 20 systems with multiple planets, some in resonant configurations. Their diversity must originate in the properties of the protoplanetary disc of dusty gas out of which they form, the dynamics of the formation of the planetary core, and the subsequent interaction of the planet with the surrounding disc, with other planets, and with the central star.Over the past decade, there has been significant progress on the theoretical aspects of the planet formation process. Two viable models of planet formation have been explored, core accretion (growth of dust into planets through mutual collisions) and gravitational instability in the disc, and several modes of angular momentum e