Magnetic fields in early-type stars

TL;DR

Recent advances in high-resolution spectropolarimetry have significantly improved our understanding of magnetic fields in early-type stars, revealing detailed surface structures and their interactions with stellar winds.

Contribution

This paper reviews recent spectropolarimetric observations and statistical analyses that enhance our understanding of magnetic properties and phenomena in early-type stars.

Findings

Detection of magnetic fields in massive stars over the past 15 years

Detailed surface magnetic maps obtained via Doppler imaging

Insights into magnetic field interactions with stellar winds

Abstract

For several decades we have been cognizant of the presence of magnetic fields in early-type stars, but our understanding of their magnetic properties has recently (over the last decade) expanded due to the new generation of high-resolution spectropolarimeters (ESPaDOnS at CFHT, Narval at TBL, HARPSpol at ESO). The most detailed surface magnetic field maps of intermediate-mass stars have been obtained through Doppler imaging techniques, allowing us to probe the small-scale structure of these stars. Thanks to the effort of large programmes (e.g. the MiMeS project), we have, for the first time, addressed key issues regarding our understanding of the magnetic properties of massive (M > 8 M_sun) stars, whose magnetic fields were only first detected about fifteen years ago. In this proceedings article we review the spectropolarimetric observations and statistics derived in recent years that have formed our general understanding of stellar magnetism in early-type stars. We also discuss how these observations have furthered our understanding of the interactions between the magnetic field and stellar wind, as well as the consequences and connections of this interaction with other observed phenomena.