<Dd> L ∗ L ⊙ = 10 (M ⊙ − M ∗) / 2.5 (\ displaystyle (\ frac (L_ (*)) (L_ (\ odot))) = 10 ^ ((M_ (\ odot) - M_ (*)) / 2.5)) </Dd> <Dl> <Dd> L ∗ (\ displaystyle L_ (*)) is the star's bolometric luminosity </Dd> <Dd> L ⊙ (\ displaystyle L_ (\ odot)) is the Sun's bolometric luminosity </Dd> <Dd> M ∗ (\ displaystyle M_ (*)) is the bolometric magnitude of the star . </Dd> <Dd> M ⊙ (\ displaystyle M_ (\ odot)) is the bolometric magnitude of the Sun (approximately 4.7554). </Dd> </Dl> <Dd> L ∗ (\ displaystyle L_ (*)) is the star's bolometric luminosity </Dd> <Dd> L ⊙ (\ displaystyle L_ (\ odot)) is the Sun's bolometric luminosity </Dd>

A measurement of brightness as seen from earth is called