Norma (constellation)

Norma is a small constellation in the Southern Celestial Hemisphere between Scorpius and Centaurus, one of twelve drawn up in the 18th century by French astronomer Nicolas Louis de Lacaille and one of several depicting scientific instruments. Its name is Latin for normal, referring to a right angle, and is variously considered to represent a rule, a carpenter's square, a set square or a level.

Four of Norma's brighter stars—Gamma, Delta, Epsilon and Eta—make up a square in the field of faint stars. Gamma² Normae is the brightest star with an apparent magnitude of 4.0. Mu Normae is one of the most luminous stars known, with a luminosity half- to one million times that of the Sun. Four star systems are known to harbour planets. The Milky Way passes through Norma, and the constellation contains eight open clusters visible to observers with binoculars. The constellation also hosts Abell 3627, also called the Norma Cluster, one of the most massive galaxy clusters known.

History