Gaia's revolution in stellar variability

TL;DR

Gaia's mission has revolutionized stellar variability research by enabling detailed mapping, classification, and discovery of millions of variable stars, including white dwarfs and RR Lyrae, through multi-epoch observations and comprehensive catalogs.

Contribution

This paper provides an overview of Gaia's impact on stellar variability studies, including new data products, catalogs, and insights into the structure of the Milky Way.

Findings

Identification of thousands of variable white dwarf candidates

Detailed catalogs of variable stars from Gaia data

Revealed 3D structures of the Milky Way using RR Lyrae stars

Abstract

Stellar variability studies are now reaching a completely new level thanks to ESA's Gaia mission, which enables us to locate many variable stars in the Hertzsprung-Russell diagram and determine the various instability strips/bands. Furthermore, this mission also allows us to detect, characterise and classify many millions of new variable stars thanks to its very unique nearly simultaneous multi-epoch survey with different instruments (photometer, spectro-photometer, radial velocity spectrometer). An overview of what can be found in literature in terms of mostly data products by the Gaia consortium is given. This concerns the various catalogues of variable stars derived from the Gaia time series and also the location and motion of variable stars in the observational Hertzsprung-Russell diagram. In addition, we provide a list of a few thousands of variable white dwarf candidates derived from the DR2 published data, among them probably many hundreds of new pulsating white dwarfs. On a very different topic, we also show how Gaia allows us to reveal the 3D structures of and around the Milky Way thanks to the RR Lyrae stars.