Ultraviolet Spectropolarimetric Diagnostics of Hot Star Magnetospheres

TL;DR

This paper explores how upcoming UV spectropolarimetric missions can diagnose hot star magnetospheres, testing how magnetic fields influence stellar spin-down and mass loss, which affects stellar evolution.

Contribution

It assesses the capabilities of future UV spectropolarimetric observatories to study hot star magnetospheres and their impact on stellar angular momentum and mass-loss processes.

Findings

Potential to distinguish magnetic from non-magnetic star evolution.

Expected to measure magnetic field strengths and plasma properties.

Insights into the role of magnetospheres in stellar evolution.

Abstract

Several space missions and instruments for UV spectropolarimetry are in preparation, such as the proposed NASA MIDEX Polstar project, the proposed ESA M mission Arago, and the Pollux instrument on the future LUVOIR-like NASA flagship mission. In the frame of Polstar, we have studied the capabilities these observatories would offer to gain information on the magnetic and plasma properties of the magnetospheres of hot stars, helping us test the fundamental hypothesis that magnetospheres should act to rapidly drain angular momentum, thereby spinning the star down, whilst simultaneously reducing the net mass-loss rate. Both effects are expected to lead to dramatic differences in the evolution of magnetic vs. non-magnetic stars.