Starspot properties and photometric parameters of transiting planets and their host stars

Abstract

To begin understanding how the architecture of hot Jupiter planetary systems can be so radically different from that of our own solar system, requires the dynamical evolution of planets to be known. By measuring the sky-projected obliquity ? of a system it is possible to determine the dominant process in the dynamical evolution.

If a transiting exoplanet that crosses the disc of its host star passes over a starspot, then the amount of received intensity from the star will change. By modelling the position of the anomaly in the lightcurve it is possible to precisely determine the position of the starspot on the stellar disc. If the position of the starspot can be found at two distinct times using two closely spaced transits, then it is possible to measure. Before now there was no definitive model capable of accurately modelling both a planetary transit and a starspot.

This research focuses on the development of prism which is capable of accurately modelling a transit containing a starspot anomaly. Due to the nature of the parameter space a new optimisation algorithm was developed, gemc, which is a hybrid between a genetic algorithm and MCMC.