Planetary Science Seminar

Abstract: Hot Jupiters can experience mass loss driven by heating from UV radiation from their host stars. This flow is often controlled by magnetic fields: near the planetary surface, the magnetic pressure dominates the ram pressure of the outflow by several orders of magnitude. Magnetically controlled planetary outflows are significantly different from previous spherical models: The outflow rates are smaller, and the flow is launched primarily from the polar regions. After leaving the vicinity of the planet, the flow must connect onto the background environment provided by the stellar wind and the stellar magnetic field. We also compare two different geometries for the background stellar magnetic field: In the first case, the stellar field is assumed to retain the form of a dipole, which is anti-aligned with the dipole field of the planet. In the second case, the stellar outflow opens up the stellar magnetic field structure so that the background field at the location of the planet is perpendicular to the planetary dipole. Using numerical simulations, we consider the launch of the planetary wind with these field configurations.