# Massive Stars: From the VLT to the ELT

## TL;DR

This paper reviews recent advances in massive star research facilitated by new telescopes and introduces a large VLT survey that tests stellar wind models across different metallicities, with future prospects for ELTs.

## Contribution

It presents the first empirical test of metallicity dependence of stellar wind intensity using VLT data and discusses future ELT observations of massive stars beyond the Local Group.

## Key findings

- Good agreement between observed and theoretical wind metallicity dependence.
- First empirical validation of stellar wind models across metallicities.
- Future ELTs will enable spatially-resolved studies of massive stars beyond the Local Group.

## Abstract

New facilities and technologies have advanced our understanding of massive stars significantly over the past 30 years. Here I introduce a new large survey of massive stars using VLT-FLAMES, noting the target fields and observed binary fractions. These data have been used for the first empirical test of the metallicity dependence of the intensity of stellar winds, finding good agreement with theory -- an important result for the evolutionary models that are used to interpret distant clusters, starbursts, and star-forming galaxies. Looking ahead, plans for future Extremely Large Telescopes (ELTs) are now undergoing significant development, and offer the exciting prospect of observing spatially-resolved massive stars well beyond the Local Group.