The Hertzsprung Russell Diagram is the "Rosetta Stone" of stellar astronomy and it's simple, very simple. So to put it simply, it's just a graph that plots lots of stars' luminosities against their surface temperatures. As simple as that sounds, it is the key to understanding stellar evolution.
In case you thought "Rosetta Stone" is some sort of educational software for… Continue
Added by Brad Snowder on April 5, 2014 at 11:53pm —