Lyons Groups of Galaxies (or LGG) is an astronomical catalog of nearby groups of galaxies complete to a limiting apparent magnitude B0=14.0 with a recession velocity smaller than 5,500 km/s. The catalogue was obtained from the Lyon-Meudon Extragalactic Database. Two methods were used in group construction: a percolation method derived from Huchra and Geller [1] and a hierarchical method initiated by R. Brent Tully.[2] The catalog is a synthesized version of the two results.
The LGG includes 485 groups and 3,933 member galaxies.