(astronomy) Type of galaxy that is very luminous at radio wavelengths.

(astronomy) A spiral galaxy in the Local Group and closest to the Milky Way, visible to the naked eye in the constellation of Andromeda, the brightest of the Messier objects and often referred to by its designation M31.

(astronomy, galaxies) plural of galaxy cluster

(astronomy, galaxies) A cluster of hundreds of galaxies.

plural of galaxy group

(astronomy) A group of galaxies that hold together gravitationally.

(astronomy) Any of a class of galaxies that have nuclei with excessive amounts of ultraviolet emissions.

Synonym of spiral galaxy

plural of galaxy filament

(cosmology) A massive, thread-like formation of gravitationally bound galaxies forming the boundaries between large voids in the universe.