# 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}