An Etymological Dictionary of Astronomy and Astrophysics

A list of 100 compact groups of galaxies that were identified by a systematic search of the → Palomar Observatory Sky Survey red prints. Each group contains four or more galaxies, has an estimated mean surface brightness brighter than 26.0 magnitude per arcsec² and satisfies an isolation criterion.

See also: Hickson, Paul, 1982, ApJ 255, 382; → compact; → group.