Cool Stars in the Hertzsprung-Russell Diagram

TL;DR

This paper introduces red supergiants within the Hertzsprung-Russell diagram, summarizing recent research, progress, and future directions in understanding these massive stars for the focus meeting.

Contribution

It provides a concise overview of red supergiants, highlighting recent developments, challenges, and potential pathways for future research in the field.

Findings

Recent activity has advanced understanding of red supergiants.

Identified key areas where progress is needed.

Suggested approaches for future research.

Abstract

As the opening review to the focus meeting ``Stellar Behemoths: Red Supergiants across the Local Universe'', I here provide a brief introduction to red supergiants, setting the stage for subsequent contributions. I highlight some recent activity in the field, and identify areas of progress, areas where progress is needed, and how such progress might be achieved.