Dr Sijme-Jan Paardekooper's Project Abstracts

Both of the projects below can be adapted into any of the three project types. 

Planets form in circumstellar gas discs around young stars. We know from the current population of extrasolar planets that there is a wide variety in outcomes of the process of planet formation. For example: Jupiter-like planets can be found in orbits ranging from less than a day long (!) to more close to a thousand years long (!). It is a huge theoretical challenge to come up with models that can realistically account for such diversity: our knowledge of planet formation still has some big holes in it. The projects below are exploring some of the processes that are not understood and where progress is to be made. They are offered in all formats: BSc Project, MSci Review Project, MSci Research/Investigative Project. Prerequisites for all projects are a programming background and an interest in numerical modeling.

1) Structure of embedded protoplanets

Gas giant planets like Jupiter are thought to form when a solid core becomes massive enough to attract large amounts of gas from the surrounding disc. The core mass at which this happens is called the critical core
mass. This core mass is of great importance for determining the final masses of planets, in the Solar system as well as for extrasolar planets.

In this project spherically symmetric models of young planets embedded in circumstellar discs will be investigated. After a critical review of the literature, we will numerically solve the structure equations under various assumptions and study the stability of the solutions.

2) Planet migration

While embedded in the protoplanetary disc, planets interact gravitationally with it, which leads to orbital migration. The character of the interaction depends on planet mass, but in all cases migration appears to be too efficient for planets to end up between 1 and 10 Astronomical Units.

In this project we will look at simplified models of migrating planets, building a numerical code that solves for the evolution of the disc and the backreaction onto the planet. Such a model can be applied to several outstanding problems in planet migration.