The Hubble–Reynolds law models the
surface brightness of
elliptical galaxies as
:
Where
is the
surface brightness at radius
,
is the central brightness, and
is the radius at which the surface brightness is diminished by a factor of 1/4. It is asymptotically similar to the
De Vaucouleurs' law de Vaucouleurs's law, also known as the de Vaucouleurs profile or de Vaucouleurs model, describes how the surface brightness I of an elliptical galaxy varies as a function of apparent distance R from the center of the galaxy:
:
\ln I(R) = \ln I_ - ...
which is a special case of the
Sersic profile for elliptical galaxies.
The law is named for the astronomers
Edwin Hubble
Edwin Powell Hubble (November 20, 1889 – September 28, 1953) was an Americans, American astronomer. He played a crucial role in establishing the fields of extragalactic astronomy and observational cosmology.
Hubble proved that many objects ...
and
John Henry Reynolds John Reynolds may refer to:
Entertainment
* John Reynolds (actor) (born 1991), American actor and writer
* John Reynolds (musician), record producer, the first husband of singer Sinéad O'Connor
* John Reynolds (writer) (1588–1655), English merc ...
. It was first formulated by Reynolds in 1913 from his observations of galaxies (then still known as nebulae). It was later re-derived by Hubble in 1930
specifically in observations of elliptical galaxies.
References
Astrophysics
Equations of astronomy
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