Variable stars in clusters

The main objective of this work is the analysis of multiple types of variable stars within star clusters to better understand Gaia and its ability to detect variable sources and to more precisely characterize the properties of these systems. To achieve this, extensive catalogs of variable stars from Gaia and various literature sources were compiled. For each star, a membership probability was estimated by comparing its astrometry with that of the corresponding cluster.Currently, the analysis of RR Lyrae stars (RRLs) represents one of the most comprehensive studies conducted using a homogeneous set of astrometry and photometry, comprising 2824 RRLs located in 115 Galactic globular clusters. It was found that approximately eighty percent of all previously identified RRLs in the literature were correctly classified by the Specific Object Study (SOS) and RRL classifier developed for Gaia. Most of the missing sources are concentrated in the central regions of the densest globular clusters, such as omega Centauri. Furthermore, no evidence of spurious sources was detected in the analysis from Gaia, suggesting that the algorithms for detecting RRLs are robust even in the most crowded regions of the sky. Unexpectedly, the Oosterhoff dichotomy was not observed in this dataset, indicating that the traditional way of dividing clusters based on their RRL population may not be accurate.Results for Type II Cepheids (T2CEP) indicate that the completeness of Gaia catalogs for this type of stars is around seventy percent. Preliminary results for long-period variables (LPVs) suggest that Gaia has detected the largest number of LPVs (approximately three thousand) in clusters to date.Finally, recent efforts to identify all types of variable stars in open clusters are presented, demonstrating how this information can be used to constrain their ages.