If you sampled the hundreds of billions of stars in any galaxy and plotted their luminosity (their brightness measured from a fixed distance — so, in other words, their "true" brightness) and their ...

A simple diagram, which celebrates its centennial this year, continues to serve as the most essential conceptual tool in stellar astrophysics Modern astronomy paints a vivid picture of the universe ...

If you've ever taken an introductory astronomy class, you've probably seen the Hertzsprung-Russell (HR) diagram. This graph maps out the life cycle of stars by plotting their temperature against their ...