Worlds of David Darling
Encyclopedia of Science
   
Home > Encyclopedia of Science

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


Related category

   • ASTRONOMICAL QUANTITIES