(distant bright red galaxies in the Sloan Digital Sky Survey)
The term luminous red galaxy (LRG) was used for the members of
a sample selected from Sloan Digital Sky Survey (SDSS) observational data, consisting
of galaxies that are distant (with a redshift around 0.4),
highly-luminous, and a reddish color. These were fainter than
SDSS's main galaxy sample, and were included as targets of the
subsequent Baryon Oscillation Spectroscopic Survey (BOSS).