|This article does not cite any references or sources. (December 2009)|
Recessional velocity is the rate at which an object is moving away, typically from Earth.
Application to cosmology 
Recessional velocity is most pertinent to distant galaxies, which (due to Hubble's Law) redshift proportionally to their distance from the Earth. The redshift is usually interpreted as due to recessional velocity, which can be calculated according to the formula:
where is the Hubble constant, is the intervening distance, and is the recessional velocity, generally measured in km/s.
|This astronomy-related article is a stub. You can help Wikipedia by expanding it.|