Astrophysics (Index)About

ultra diffuse galaxy

(a galaxy with extremely low luminosity)

An ultra diffuse galaxy (UDG) is a galaxy with a very low luminosity, essentially an extreme example of an low-surface-brightness galaxy. UDGs lack the gas to feed star formation and tend to have older stars, and if star formation has become miniscule, a greater percentage of its stars are late-type, with low luminosity.

(galaxy type)
Further reading: