The origins of the magnetic field in tip-RGB, AGB and post-AGB stars

TL;DR

This paper reviews recent discoveries of weak magnetic fields in evolved cool giant stars, focusing on their origins and the mechanisms behind magnetic field generation in tip-RGB, AGB, and post-AGB stars.

Contribution

It provides a summary of recent observational findings and discusses potential magnetic field generation mechanisms in late-stage giant stars.

Findings

Detection of weak magnetic fields in evolved giants

Discussion of magnetic activity in the upper H-R diagram

Analysis of possible magnetic field generation mechanisms

Abstract

During the last decade and a half, the new generation spectropolarimeter Narval at Pic du Midi, France allowed the study of weak magnetic fields in cool giant stars that are fairly evolved after main sequence. We present a short summary on the recent knowledge on the magnetic fields and activity in giants situated in the upper right part of the Hertzsprung-Russel (H-R) diagram and discuss on the possible mechanisms for magnetic field generation in the asymptotic giants branch (AGB) and post-AGB stars.