Magnetic fields of cool giant and supergiant stars: models versus observations

TL;DR

This paper reviews recent observational and theoretical advances in understanding magnetic fields in cool giant and supergiant stars, highlighting direct imaging, detections, and the origins of stellar magnetism.

Contribution

It provides a comprehensive overview of current knowledge, comparing models with recent observations to elucidate the origin and characteristics of magnetic fields in these stars.

Findings

Magnetic fields have been detected in numerous cool giants and supergiants.

Starspots have been directly imaged on active giant stars.

Theoretical models are discussed in relation to recent observational data.

Abstract

The recent years have brought great advances in our knowledge of magnetic fields in cool giant and supergiant stars. For example, starspots have been directly imaged on the surface of an active giant star using optical interferometry, and magnetic fields have been detected in numerous slowly rotating giants and even on supergiants. Here, I review what is currently known of the magnetism in cool giant and supergiant stars, and discuss the origin of these fields and what is theoretically known about them.