Interacting Fields and Flows: Magnetic Hot Jupiters

TL;DR

This paper uses MHD simulations to study magnetic interactions between hot Jupiters and their host stars, predicting ECMI emission but finding it is suppressed by circumplanetary material.

Contribution

It introduces detailed MHD simulations of star-planet magnetic interactions, revealing the suppression of ECMI emission by evaporated planetary atmospheres.

Findings

ECMI emission is predicted but cannot escape the system.

Evaporated planetary atmospheres create high plasma frequencies.

Magnetic interactions influence planetary atmospheric dynamics.

Abstract

We present Magnetohydrodynamic (MHD) simulations of the magnetic interactions between a solar type star and short period hot Jupiter exoplanets, using the publicly available MHD code PLUTO. It has been predicted that emission due to magnetic interactions such as the electron cyclotron maser instability (ECMI) will be observable. In our simulations, a planetary outflow, due to UV evaporation of the exoplanets atmosphere, results in the build-up of circumplanetary material. We predict the ECMI emission and determine that the emission is prevented from escaping from the system. This is due to the evaporated material leading to a high plasma frequency in the vicinity of the planet, which inhibits the ECMI process.