Germano Sacco, INAF-Osservatorio Astrofisico di Arcetri, Florence, Italy — November 18, 2024

Abstract
Stars do not form in isolation but in stellar systems composed of a number of siblings ranging from a few tens to several thousands. Understanding the formation and evolution of these stellar systems as well as the processes driving the evolution of stars before they arrive on the main sequence is a key question in galactic astronomy. During the last decade the combination of astrometric, photometric and spectroscopic data from the Gaia space mission
and its associated ground-based surveys have lead to several progress in this field. 
I will start my talk with a review of the current paradigm describing the dynamical evolution of young stellar systems and pre-main sequence stars, highlighting recent results obtained, in particular, with observations of young clusters carried out in the context of the Gaia-ESO survey. Then, I will present two new spectroscopic surveys of young stars that will start next year with the two new ESO multi-object spectrographs MOONS at VLT and 4MOST at VISTA. Finally, I will conclude by discussing how deep learning algorithms can be used to analyse the spectra that will be gathered with this new generation of instruments.