The Gaia Focused Product Release Catalog of Long-Period Variable candidates

Author(s)
Michele Trabucchi, Nami Mowlavi, Thomas Lebzelter
Abstract

Long-period variables (LPVs) represent the late evolutionary stages of low- to intermediate-mass stars (on the Asymptotic Giant Branch, AGB) or massive stars (Red Supergiants, RSGs). They display periodic variability attributed primarily to stellar pulsation in several low-order modes, possibly at the same time. They also exhibit long-term periodic changes, dubbed "long secondary periods" (LSPs), whose nature is still unclear. Understanding these variability processes is crucial to study the evolution of these stars and the mass-loss process that leads to their death, as well as to the enrichment of the interstellar medium by their nucleosynthesis products. In 2016, the second Gaia Data Release (Gaia DR2) delivered photometric time series for over 150'000 LPV candidates based on 22 months of observations. With Gaia DR3 (2022), this number increased to more than 2.3 millions, extending the span of the time series up to 34 months. Among them, 10'000 sources brighter than G=14mag were selected and published with their radial velocity time series as part of the Gaia Focused Product Release (FPR) of October 2023. While measuring the mean radial velocity of a star is a key ingredient to understanding the dynamics of the Galaxy's stellar content, Gaia's multi-epoch observations allow us to monitor radial velocity variability - in parallel to photometric variability. I will present the purpose, construction and content of the FPR catalog of LPVs, focusing on the potential provided by the combination of epoch photometry and radial velocity data distinguishing between different types of variability such as pulsation, LSPs, and ellipsoidal variations. The LPV catalogue published in the FPR is an appealing teaser for what is expected for DR4. It has already substantially expanded the availability of epoch radial velocity data for long-period variables, and is of unprecedented value for investigating the variability of evolved red giants.

Organisation(s)
Department of Astrophysics
External organisation(s)
University of Padova, Université de Genève
Publication date
07-2024
Peer reviewed
Yes
Austrian Fields of Science 2012
103003 Astronomy, 103004 Astrophysics
Portal url
https://ucrisportal.univie.ac.at/en/publications/3e17226f-751c-4854-b75c-380a403c108a