Astrophysics (Index)About

redshift-magnitude relation

(Magnitude-redshift relation)
(how apparent magnitude depends on redshift)

The redshift-magnitude relation (or magnitude-redshift relation) is a function of redshift (or distance) that yields (effectively) the distance modulus associated with that redshift: the difference between apparent magnitude and absolute magnitude. This was of great interest when the expansion of the universe was first being proposed.

It is also of current interest: like the redshift-angular size relation, it is straight-forward given some simplifying approximations: in this case, constant. However, at cosmological distances, various models as well as observation reveal it is not so simple, and observation can be used to select and tweak models.

Further reading: