Norma (constellation)

Norma

Constellation
List of stars in Norma
Abbreviation	Nor
Genitive	Normae
Pronunciation	/ˈnɔːrmə/, genitive /ˈnɔːrmiː/
Symbolism	the carpenter's square
Right ascension	15h 12m 13.6119s to 16h 36m 08.3235s[1]
Declination	−42.27° to −60.44°[1]
Quadrant	SQ3
Area	165 sq. deg. (74th)
Main stars	4
Bayer/Flamsteed stars	13
Stars with planets	4
Stars brighter than 3.00m	0
Stars within 10.00 pc (32.62 ly)	0
Brightest star	γ2 Nor (4.01m)
Messier objects	0
Meteor showers	Gamma Normids
Bordering constellations	Ara Lupus Circinus Triangulum Australe Scorpius
Visible at latitudes between +30° and −90°. Best visible at 21:00 (9 p.m.) during the month of July.

Norma is a small constellation in the Southern Celestial Hemisphere between Ara and Lupus, 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. It remains one of the 88 modern constellations.

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 between a quarter million and 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.

From the perspective of an observer on Earth, the Norma Arm of the Milky Way passes through the constellation Norma, and it's from the constellation that the arm's name is derived.