Hertzsprung-Russell Diagram

Shows the relation between stellar
Brightness (absolute magnitude) and
Temperature
Diagram is made by plotting (graphing) each star’s
Luminosity (brightness) and
Temperature

Parts of an H-R diagram
Main-sequence stars
90 percent of all stars
Band through the center of the H-R diagram
Sun is in the main-sequence
Giants (or red giants)
Very luminous
Large
Upper-right on the H-R diagram

Parts of an H-R diagram
Giants (or red giants)
Very large giants are called supergiants
Only a few percent of all stars
White dwarfs
Fainter than main-sequence stars
Small (approximate the size of Earth)
Lower-central area on the H-R diagram
Not all are white in color
Perhaps 10 percent of all stars