# Stellar magnetic activity and exoplanets

## TL;DR

This paper reviews the relationship between stellar magnetic activity and exoplanets, emphasizing recent spectropolarimetric measurements and their implications for understanding star-planet interactions.

## Contribution

It provides an overview of recent magnetic field measurements and discusses potential effects of exoplanets on stellar magnetic activity, highlighting new observational insights.

## Key findings

- Magnetism correlates with stellar rotation and internal structure.
- Spectropolarimetric measurements offer detailed magnetic field data.
- Exoplanets may influence host star activity, but evidence is mixed.

## Abstract

It has been proposed that magnetic activity could be enhanced due to interactions between close-in massive planets and their host stars. In this article, I present a brief overview of the connection between stellar magnetic activity and exoplanets. Stellar activity can be probed in chromospheric lines, coronal emission, surface spot coverage, etc. Since these are manifestations of stellar magnetism, these measurements are often used as proxies for the magnetic field of stars. Here, instead of focusing on the magnetic proxies, I overview some recent results of magnetic field measurements using spectropolarimetric observations. Firstly, I discuss the general trends found between large-scale magnetism, stellar rotation, and coronal emission and show that magnetism seems to be correlated to the internal structure of the star. Secondly, I overview some works that show evidence that exoplanets could (or not) act as to enhance the activity of their host stars.