Abstract

This Focus Meeting will bring together astronomers who study resolved massive stars, the integrated light of stellar clusters, and their effects on their host galaxies, combining state-of-the-art rest-frame UV spectra and photometric observations with models. This meeting will have a significant interdisciplinary component, focusing on the interplay between massive stars and their host galaxies (e.g. the consequences of environment on the formation and evolution of massive stars and clusters, and their subsequent feedback in terms of ionizing photon production, mass-loss due to winds, and properties of the ISM). The topics and the timing of the meeting are largely driven by the data release of the HST ULLYSES and CLASSY surveys. The former is a complete spectroscopic UV survey of individual massive, metal-poor stars in the Local Group, and the latter provides integrated high-resolution UV spectra of young massive star clusters in the nearby universe.