Hertzsprung–Russell Diagram

Each point is a real catalogued star, placed by its surface temperature (hot on the left) and luminosity (bright at the top) — both from curated literature values. The diagonal band is the main sequence where stars spend most of their lives; cool luminous stars at upper-right are giants & supergiants; hot faint stars at lower-left are white dwarfs. Hover for details, click to open a star.