Distance modulus and the inverse square lawWatch
and then further research I discover about standard candles and more specifically cepheid variables and type 1a supernovae. As far as I understand we use this standard candles of known luminosity, then measure the apparent magnitude and then use the inverse square law to work out the distance. My question is, is using the inverse square law different to using the distance modulus or is the distance modulus just an expression of the inverse square law? So when using standard candles do you use the known luminosity to work out absolute magnitude, then measure the apparent magnitude and then work out the distance using the distance modulus?