Effective induction heating around strongly magnetized stars

Understand

Planets that are embedded in the changing magnetic fields of their host stars can experience significant induction heating in their interiors caused by the planet's orbital motion.

• For induction heating to be substantial, the planetary orbit has to be inclined with respect to the stellar rotation and dipole axes.
• Using WX~UMa, for which the rotation and magnetic axes are aligned, as an example, we show that for close-in planets on inclined orbits, induction heating can be stronger than the tidal heating occurring inside Jupiter's satellite Io; namely, it can generate a surface heat flux exceeding 2\,W\,m$^{-2}$.
• An internal heating source of such magnitude can lead to extreme volcanic activity on the planet's surface, possibly also to internal local magma oceans, and to the formation of a plasma torus around the star aligned with the planetary orbit.