A Spectropolarimetry Survey of Asymptotic Giant Branch Stars and their Circumstellar Envelopes

Asymptotic Giant Branch stars (AGB stars) descend from medium mass, main sequence stars whose cores have run out of both hydrogen and helium. While these stars continue to burn helium in their inner shell and hydrogen in a secondary shell, they become highly convective. This process brings new nuclei to the surface of the star where heat-resistant components condense into dust. The photons emitted by the star create radiation pressure on the dust grains, which in turn causes the ejection of particles from the star (i.e. stellar winds). The resulting stellar winds collide with the interstellar medium (ISM), creating a transition region between the AGB star and the ISM. This region is known as an astrosheath. In this talk, we summarize our understanding of how shocks, magnetic fields, and grain mineralogy affect dust grain alignment in the astrosheath of ABG stars. We also describe the techniques and software used to prepare a new proposal for time on the South African Large Telescope (SALT) so we can study a carefully selected AGB star.