# Extragalactic Supergiants

## TL;DR

Blue supergiant stars are extremely bright objects that serve as valuable tools for studying distant galaxies, their environments, and properties through spectral analysis, advancing our understanding of stellar evolution and galactic characteristics.

## Contribution

This review summarizes recent advances in the spectral analysis of extragalactic blue supergiants and their applications in probing galaxy properties across different metallicities.

## Key findings

- Spectroscopic analysis constrains stellar evolution models.
- Blue supergiants help determine galaxy distances.
- Studies reveal chemical compositions and extinction laws.

## Abstract

Blue supergiant stars of B and A spectral types are amongst the visually brightest non-transient astronomical objects. Their intrinsic brightness makes it possible to obtain high quality optical spectra of these objects in distant galaxies, enabling the study not only of these stars in different environments, but also to use them as tools to probe their host galaxies. Quantitative analysis of their optical spectra provide tight constraints on their evolution in a wide range of metallicities, as well as on the present-day chemical composition, extinction laws and distances to their host galaxies. We review in this contribution recent results in this field.