Magnetic induction processes in hot Jupiters, application to KELT-9b

The small semi-major axes of Hot Jupiters lead to high atmospheric temperatures up several thousand Kelvin. Under these conditions, thermally ionised metals provide a rich source charged particles and thus build sizeable electrical conductivity. Subsequent electromagnetic effects, such as the induction electric currents, Ohmic heating, magnetic drag, or weakening zonal winds have far been considered mainly in framework linear, steady-state model induction. For with an equilibrium temperature $T_{eq} > 1500$ K, fields is runaway process that can only be stopped by non-linear feedback. example, back-reaction field onto flow via Lorentz force occurrence instabilities. Moreover, we discuss possibility self-excited dynamos. Our results suggest induced currents become independent conductivity internal field, but instead are limited planetary rotation rate wind speed. As explicit characterise for hottest exoplanet, KELT-9b calculating along $P-T$-profiles day- nightside. Despite varying between 3000 K 4500 resulting attains elevated value roughly 1 S/m throughout atmosphere. predominately horizontal might reach saturation strength 400 mT, exceeding two orders magnitude.