Building planetary systems

Astronomy Unit Seminars
Dr Richard Alexander (U. Leicester)
Sijme-Jan Paardekooper
October 17th, 2014 at 14:30
GO Jones Room 610

The last few years have seen an explosion in our knowledge of extra-solar planetary systems. We now know that exoplanets have an extraordinary range of properties, and almost every conceivable planetary architecture seems to exist in nature. Planets form in cold discs of dust and gas around young, newly-formed stars, and in this talk I will try to explain how such a diverse population of planets formed from these relatively homogenous initial conditions. I will first review the physics of protoplanetary disc evolution, and discuss the conditions under which planets form and migrate. I will show how disc evolution and dispersal influences migrating planets, leading to "deserts" and "pile-ups" in the distribution of exoplanets. I will then consider the new class of compact planetary systems discovered by Kepler, and discuss under what conditions it is possible to build these systems through migration. Finally I will present models of disc evolution in binary systems, and consider the formation and dynamics of circumbinary planets such as Kepler-16b.