Convection and dynamo action in B stars

TL;DR

This study models magnetic field generation in the convective cores of B stars using 3D simulations, revealing strong, complex magnetic fields that influence the star's interior dynamics.

Contribution

It demonstrates the formation of intense, dynamic magnetic fields in B star cores through advanced 3D simulations, highlighting their penetration into radiative zones.

Findings

Magnetic fields up to 900 kG develop in the core.

Fields exhibit reversals and hemispheric shifts over time.

Core convection can generate significant magnetic structures.

Abstract

Main-sequence massive stars possess convective cores that likely harbor strong dynamo action. To assess the role of core convection in building magnetic fields within these stars, we employ the 3-D anelastic spherical harmonic (ASH) code to model turbulent dynamics within a 10 solar mass main-sequence (MS) B-type star rotating at 4 times the solar rate. We find that strong (900 kG) magnetic fields arise within the turbulence of the core and penetrate into the stably stratified radiative zone. These fields exhibit complex, time-dependent behavior including reversals in magnetic polarity and shifts between which hemisphere dominates the total magnetic energy.