A

David

Darling

distance modulus

The distance modulus is the difference between the apparent magnitude (m) of an astronomical object, such as star, and its absolute magnitude (M). The distance modulus is given by

 

m - M = 5 log d - 5

 

where d is the distance in parsecs.

 

Rearranging this enables d to be calculated from the formula

 

d = 10(m - M + 5)/5