Class Color

source code

Convert a color to a flux ratio and back

B-V = -2.5log10(FB) + CB - (-2.5log10(FV) + CV) B-V = -2.5log10(FB) + CB + 2.5log10(FV) - CV B-V = -2.5log10(FB/FV) + (CB-CV)

and thus

FB/FV = 10 ** [((B-V) - (CB-CV)) / (-2.5)]

where

CB = 2.5log10[FB(m=0)] CV = 2.5log10[FV(m=0)]

Stromgren colour indices:

m1 = v - 2b + y c1 = u - 2v + b Hbeta = HBN - HBW