Speaker
Description
Recent Gaia observations, together with advances in the theory of stellar evolution, open up the possibility to study color-magnitude diagrams of Galactic globular clusters with unprecedented accuracy. In particular, lists of cluster members, their metallicity, helium mass fraction, age, distance from the Sun, and reddening can be precisely determined. We present our study of 35 Galactic globular clusters based on the data from Gaia DR3, expected Gaia DR4, and the best ground-based data cross-identified with Gaia. We fit these data by four independent, most developed models and related isochrones, which account for all the essential physical processes. Precise sets of the cluster parameters and member lists will bring novel constraints on axion-like particles and other new-physics scenarios, with first results to be presented in this talk.
