Department of Physics, Engineering Physics & Astronomy

Department of Physics, Engineering Physics & Astronomy
Department of Physics, Engineering Physics & Astronomy

Departmental Colloquium - Formation and stability of planetary systems

Hanno Rein,
Toronto

Friday November 17th, 2017
1:30 p.m. Stirling A

Abstract:

The diverse population of extrasolar planets keeps challenging theories of planet formation. Multi-planetary systems are of particular interest as their dynamical architectures allow us to constrain an otherwise unobservable formation phase.

I'll show how a simple stability requirement together with machine learning tools can be used to constrain orbital parameters of planetary systems such as HL-Tau and Trappist-1. Some of the dynamical properties we find in the these systems can be explained by a turbulent protoplanetary disk and stochastic planet migration. Saturn's rings can be thought of as a small scale version and test bed of the early Solar System. I'll show evidence that stochastic migration can be directly observed in moonlets around Saturn.

I'll finally talk about some of the numerical challenges when running accurate long term simulations of planetary systems. Even though we are solving differential equations that have been known since Newton's time, several breakthroughs were made only very recently with the help of clever numerical algorithms. Among these is the discovery that one percent of all realization of the Solar System lead to collisions between planets within the life-time of the Sun.