One method used by observational astronomers to estimate the distance to an object by comparing its apparent magnitude to its absolute magnitude.

Goes something like this: M - m = 5 * log (d / 10pc), where M is absolute magnitude, m is apparent magnitude, and d is the distance to the object in parsecs.
Y'know, if you log in, you can write something here, or contact authors directly on the site. Create a New User if you don't already have an account.