# The First Optical Spectra of Wolf Rayet Stars in M101 Revealed with Gemini/GMOS

## TL;DR

This study confirms the presence of Wolf Rayet stars in M101 through spectroscopic analysis, revealing their distribution across different metallicities and their association with star-forming regions, aiding future supernova progenitor research.

## Contribution

First optical spectra of Wolf Rayet stars in M101 obtained with Gemini/GMOS, confirming photometric candidates and analyzing their properties and environments.

## Key findings

- Confirmed 15 WR stars spectroscopically
- WR stars found at various metallicities, with WC favoring metal-rich regions
- Most WR stars are associated with HII regions

## Abstract

Deep narrow-band HST imaging of the iconic spiral galaxy M101 has revealed over a thousand new Wolf Rayet (WR) candidates. We report spectrographic confirmation of 10 HeII emission line sources hosting 15 WR stars. We find WR stars present at both sub- and super-solar metalicities with WC stars favouring more metal-rich regions compared to WN stars. We investigate the association of WR stars with HII regions using archival HST imaging and conclude that the majority of WR stars are in or associated with HII regions. Of the 10 emission lines sources, only one appears to be unassociated with a star-forming region. Our spectroscopic survey provides confidence that our narrow-band photometric candidates are in fact bonafide WR stars, which will allow us to characterise the progenitors of any core-collapse supernovae that erupt in the future in M101.