The Hertzsprung-Russell diagram allows astronomers to map out the complete life history of a star. Learn all about this famous diagram in the fifth episode of "We Don't Planet." Skip to main content ...

Stars are often organized using what's known as the Hertzsprung-Russell (H-R) diagram. Stars like Earth’s sun that burn hydrogen into helium are in a group called the "main-sequence." You may like ...

Finally, there is a second large group outside the main sequence. Stars in this group are all located in the upper area of the Hertzsprung- Russell diagram with very high absolute brightness values.