Mixing in two magnetic OB stars discovered by the MiMeS collaboration

TL;DR

This study investigates whether magnetic OB stars exhibit more internal mixing than non-magnetic stars, finding that strong magnetic fields do not necessarily lead to deeper surface mixing in main-sequence OB stars.

Contribution

It provides the first NLTE abundance analysis of two magnetic OB stars, challenging the assumption that magnetic fields always enhance internal mixing.

Findings

No CN-cycled material detected at the surface of the two magnetic stars.

Magnetic fields are not sufficient for deep mixing in main-sequence OB stars.

Results suggest other factors influence mixing processes in these stars.

Abstract

Recent observational and theoretical arguments suggest that magnetic OB stars may suffer more mixing than their non magnetic analogs. We present the results of an NLTE abundance study revealing a lack of CN-cycled material at the surface of two magnetic stars discovered by the MiMeS project (NGC2244 #201 and HD 57682). The existence of a strong magnetic field is therefore not a sufficient condition for deep mixing in main-sequence OB stars.