Could star-planet magnetic interactions lead to planet migration and influence stellar rotation ?

TL;DR

This paper investigates how magnetic and tidal star-planet interactions influence the orbital migration of hot Jupiters and the rotational evolution of their host stars, using a comprehensive numerical model.

Contribution

It introduces a coupled model that integrates magnetic and tidal effects to better predict star-planet system evolution.

Findings

Magnetic effects can dominate tidal effects in certain evolutionary phases.

Planet migration can be significant due to magnetic interactions.

Stellar rotation is notably affected by star-planet magnetic interactions.

Abstract

The distribution of hot Jupiters, for which star-planet interactions can be significant, questions the evolution of exosystems. We aim to follow the orbital evolution of a planet along the rotational and structural evolution of the host star by taking into account the coupled effects of tidal and magnetic torques from ab initio prescriptions. It allows us to better understand the evolution of star-planet systems and to explain some properties of the distribution of observed close-in planets. To this end we use a numerical model of a coplanar circular star-planet system taking into account stellar structural changes, wind braking and star-planet interactions, called ESPEM (Benbakoura et al. 2019). We find that depending on the initial configuration of the system, magnetic effects can dominate tidal effects during the various phases of the evolution, leading to an important migration of the planet and to significant changes on the rotational evolution of the star. Both kinds of interactions thus have to be taken into account to predict the evolution of compact star-planet systems.