Luminosity (relative to our Sun)
1,000,000 L +x +
| x s s s s |
| xx s s s s s |
| xxx s s |
10,000 L + xxx +
| xxx g g |
| xxx g g g g |
| xxxx g g g g g g g |
100 L + xxxxx g gg g gg g g +
| xxxxxxx g g g |
| xxxxxxxxx |
| xxxxxxxxxxxx |
1 L + xxx(S)xxxx +
| w xxxxxxxxxx |
| xxxxxx |
| w w xxxxx |
1/100 L + w xxxx +
| w xxx |
| w xxx |
| w xxx |
1/10,000 L + w x +
|-------|-------|-------|-------|-------|-------|-------|
O B A F G K M
25,000 10,000 6,000 3,000
Temperature in Kelvin
x = Main sequence stars
(S) = The Sun
w = White dwarfs
g = Giants
s = Supergiants
OBAFGKM = Spectral type. See Stellar spectra.