An Etymological Dictionary of Astronomy and Astrophysics

A selection effect in observational astronomy. If a sample of objects (galaxies, quasars, stars, etc.) is flux-limited, then the observer will see an increase in average luminosity with distance, because the less luminous sources at large distances will not be detected.

See also: Named after the Swedish astronomer Gunnar Malmquist (1893-1982); → bias.