Editing Distance modulus (section)

== Different kinds of distance moduli ==
{{unreferenced | section|date=July 2023}}
Distance is not the only quantity relevant in determining the difference between absolute and apparent magnitude. Absorption is another important factor, and it may even be a dominant one in particular cases (''e.g.'', in the direction of the [[Galactic Center]]). Thus a distinction is made between distance moduli uncorrected for [[interstellar reddening|interstellar absorption]], the values of which would overestimate distances if used naively, and absorption-corrected moduli.

The first ones are termed ''visual distance moduli'' and are denoted by <math>{(m - M)}_{v}</math>, while the second ones are called ''true distance moduli'' and denoted by <math>{(m - M)}_{0}</math>.

Visual distance moduli are computed by calculating the difference between the observed apparent magnitude and some theoretical estimate of the absolute magnitude. True distance moduli require a further theoretical step; that is, the estimation of the [[interstellar absorption coefficient]].