### distance modulus

**(u)**
(apparent magnitude minus absolute magnitude)

A star or other astronomical body's **distance modulus** (**u**) is
an indication of its distance consisting of
the difference between
its apparent magnitude and its absolute magnitude.
It is directly related to the distance to the star
if there is no absorption.

u = 5 log_{10}d - 5

- u -
*distance modulus*.
- d - distance in parsecs

(*measure,EMR,logarithmic,distance,magnitude*)
http://en.wikipedia.org/wiki/Distance_modulus

**Referenced by:**

planetary nebula luminosity function (PNLF)

redshift-magnitude relation

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