A Fresh Look into the Interaction of Exoplanets Magnetosphere with Stellar Winds using MHD Simulations

TL;DR

This paper uses MHD simulations to study how exoplanet magnetospheres interact with stellar winds, considering different star types, planetary sizes, and tidal locking effects, addressing modeling challenges at close orbital distances.

Contribution

It introduces a novel approach to modeling hot Jupiter-star systems with MHD simulations, overcoming previous boundary and scaling limitations.

Findings

Simulations reveal the impact of stellar type on magnetosphere size.

Tidal locking significantly influences magnetospheric power.

Modeling at closer distances requires refined boundary conditions.

Abstract

Numerous numerical studies have been carried out in recent years that simulate different aspects of exoplanets' magnetosphere and stellar winds. These studies have focused primarily on hot Jupiters with sun-like stars. This study addresses the challenges inherent in utilizing existing MHD codes to model hot Jupiter-star systems. Due to the scaling of the system and the assumption of a uniformly flowing stellar wind at the outer boundary of the simulation, MHD codes necessitate a minimum distance of greater than 0.4 au for a Jupiter-like planet orbiting a sun-like star to avoid substantial violations of the code's assumptions. Additionally, employing the GAMERA (Grid Agnostic MHD for Extended Research Applications) MHD code, we simulate star-planet interactions considering various stellar types (Sun-like and M Dwarf stars) with both Jupiter-like and Earth-like planets positioned at varying orbital distances. Furthermore, we explore the impact of tidal locking on the total power within the magnetosphere-ionosphere systems.