Star Clusters, Page 66: [Previous Page] [Next Page] [Class Home Page] Textbook pages 392 - 401

How'd we figure out how stars evolve?

No astronomer is old enough to have actually *seen* a star evolve! However, when we plot a single stellar cluster, where all the stars have the same age and distance, then we get a glimpse of how stars evolve. Cluster at Birth. Stars to the upper left of the diagram are MASSIVE stars. Stars toward the middle, have masses like our Sun. The small stars to the lower right have masses much less than our Sun.

Cluster after 8 Million years. After just 8 million years, the most massive stars are already running out of fuel! They begin to move away from the Main Sequence as they evolve into Red Supergiant Stars.