The Magnetised Bellows of Betelgeuse

TL;DR

This paper develops a magnetised hybrid wind model for Betelgeuse, combining stellar wind theory with dust dynamics, to explain mass lifting and wind velocities, highlighting magnetic fields' role in supergiant outflows.

Contribution

It introduces a novel hybrid wind model for Betelgeuse that incorporates magnetic fields and dust, extending previous stellar wind theories to supergiants.

Findings

Magnetic fields influence the stellar wind structure of Betelgeuse.

The model predicts wind velocities consistent with observations.

Magnetic effects may be crucial in mass loss processes of supergiants.

Abstract

We present calculations for a magnetised hybrid wind model for Betelegeuse ($\alpha - $Orionis). The model is a direct application of our previously derived theory, combining a canonical Weber-Davis (WD) stellar wind with dust grains in the envelope of an AGB star \citep[see][]{Thirumalai2010}. The resulting hybrid picture provides a mechanism for solving the problem of lifting stellar material up from the photosphere \citep[e.g.][] {Harper2009,Guandalini2006,Jura1984} and into the circumstellar envelope. It also predicts wind velocities in agreement with current estimates. Our approach reveals that magnetic fields in supergiant stars like Betelgeuse \citep[see][]{Auriere2010}, may play a vital role in determining the nature of the stellar outflow and consequently, opens a new avenue of investigation in the field of hybrid stellar winds.