Bonn 2010 – wissenschaftliches Programm
EP 11.5: Vortrag
Mittwoch, 17. März 2010, 16:15–16:30, AKM
Plasma interaction between exoplanets and their host stars — •Timo Grambusch and Joachim Saur — Institut für Geophysik und Meteorologie, Universität zu Köln, Zülpicher Str. 49a, D-50674 Köln
We present a method to calculate the energy flux, which is transported by plasmawaves from exoplanets to their host stars.
In the last fourteen years more than 400 exoplanets have been discovered and most of them are so-called Hot Jupiters. Those planets have a short semi-major axis (< 0.1 AU) and a mass in the order of Jupiter’s mass. For some of these planets the stellar wind is sub-Alfvénic, which means that no fast-shock is present and an Alfvén wing forms. In this case the interaction is similar to the Io-Jupiter interaction where the Alfvén wing produces a footprint in the ionosphere of Jupiter.
For our calculations we assume that the main contribution of the energy flux is carried by the integrated Poynting flux. We discuss how the energy flux depends on the extend of the magnetosphere, the stellar wind velocity, the stellar magnetic field and other parameters. Finally, we will provide the total energy fluxes for several exoplanets, where observational hints for a planet-star connection exist.