A search for Vega-like fields in OB stars

TL;DR

This study investigates the presence of extremely weak magnetic fields in OB stars, inspired by discoveries in Vega and similar stars, using ultra-deep spectropolarimetric observations to explore a new class of magnetic stars.

Contribution

It is the first to systematically search for very weak magnetic fields in OB stars, expanding the understanding of stellar magnetism beyond previously known stronger fields.

Findings

Initial results suggest some OB stars may host very weak magnetic fields.

The study demonstrates the feasibility of ultra-deep spectropolarimetric techniques for detecting weak fields.

Future observations will further clarify the prevalence of such fields in massive stars.

Abstract

Very weak magnetic fields (with a longitudinal component below 1 Gauss) have recently been discovered in the A star Vega as well as in a few Am stars. According to fossil field scenarios, such weak fields should also exist in more massive stars. In the framework of the ANR project Imagine, we have started to investigate the existence of this new class of very weakly magnetic stars among O and B stars thanks to ultra-deep spectropolarimetric observations. The first results and future plans are presented.