Magnetic interaction of super-Earths with their host star and planet composition

Abstract

We study the magnetic field and the planet-star interactions of super Earths, extrasolar planets with masses between 1 and 10 times the mass of the Earth. We first present a model of the magnetic field of a super Earth, the dynamo model. We then list and explain several mechanisms through which magnetic energy can be released, as well as various ways through which the power dissipated can be observed. We apply our model to two recently discovered super Earths, CoRoT 7-b and GJ 1214 b. We find that emission from CoRoT 7-b is very low and thus unlikely to be observable, while emission from GJ 1214 b may be detectable with current instruments and its measurement can provide information regarding the internal composition of the planet. Further on, we discuss some special cases for detection, such as M and Ap type stars. We conclude our thesis with a generalization of our results and guidelines for future developments.