G2V

The spectral type is often devided by adding a number from 0 to 9. So the Sun is for exemple a G2

star. The line from F, via G to Kruns as follows: F8, F9, G0, G1, G2, G3, G4, G5, G6, G7, G8, G9,

K0, K1, and so on. Sometimes there will be add a Roman number to it from I to VI. This is called

the luminosity class and tells something about the phase of evolution in which the star finds and so

how big the star is. So main sequence stars are indicated with a V, sub-giants wih IV, giants with III

and supergiants with I. Sometimes white dwarfs are granted withVI. The complete spectral type of

the Sun is G2V.