Asymptotic Giant Branch Variables in the Galaxy and the Local Group

TL;DR

This paper reviews the role of AGB variables, especially Mira stars, in calibrating cosmic distances and discusses how Gaia and future telescopes will enhance understanding of their properties and mass-loss processes.

Contribution

It synthesizes recent advancements in distance measurements to AGB stars and highlights Gaia's potential to improve understanding of their mass-loss mechanisms.

Findings

Hipparcos improved distance estimates to AGB stars

Gaia will refine extragalactic distance calibration

Future telescopes will enhance infrared observations of AGB variables

Abstract

AGB variables, particularly the large amplitude Mira type, are a vital step on the distance scale ladder. They will prove particularly important in the era of space telescopes and extremely large ground-based telescopes with adaptive optics, which will be optimized for infrared observing. Our current understanding of the distances to these stars is reviewed with particular emphasis on improvements that came from Hipparcos as well as on recent work on Local Group galaxies. In addition to providing the essential calibration for extragalactic distances Gaia may also provide unprecedented insight into the poorly understood mass-loss process itself.