Finding Wolf-Rayet Stars in the Local Group

TL;DR

This paper reviews the history and importance of surveys for Wolf-Rayet stars in the Local Group, discusses their role in understanding stellar evolution, and presents new findings from a survey in the Magellanic Clouds.

Contribution

It provides a comprehensive review of Wolf-Rayet star surveys and introduces a new type of WN star discovered in the Magellanic Clouds.

Findings

Observed WC/WN ratio evolution in nearby galaxies

Identified a new type of WN star in the Magellanic Clouds

Emphasized the importance of survey completeness for stellar evolution studies

Abstract

We summarize past and current surveys for Wolf-Rayet stars among the Local Group galaxies, emphasizing both the how and the why. Such studies are invaluable for helping us learn about massive star evolution, and for providing sensitive tests of the stellar evolution models. But for such surveys to be useful, the completeness limits must be well understood. We illustrate that point in this review by following the "evolution" of the observed WC/WN ratio in nearby galaxies. We end by examining our new survey for WR stars in the Magellanic Clouds, which has revealed a new type of WN star, never before seen.