Created in the 18th century by French astronomer Nicolas-Louis de Lacaille, Norma is a small constellation in the southern celestial hemisphere that exists between Ara and Lupus. Lacaille created 12 constellations during this time period, which included Norma, and Norma is one of several constellations depicting scientific instruments.

The name Norma is Latin for normal, which refers to a right angle. There are various interpretations of what the constellation could represent in the sky, which includes a rule, a carpenter’s square, a set square or a level.

The Milky Way passes through Norma, and the constellation contains eight open clusters, which are visible to observers with binoculars. Moreover, the constellation is host to one of the most massive galaxy clusters, Abell 3627, also called the Norma Cluster.

In the sky, Norma covers 165.3 square degrees, which represents 0.401% of the night sky. This makes the constellation it ranks 74th largest of the 88 constellations in size. If you’re observing in altitudes south of 29°N, then you will be treated to the entire constellation being visible.

	Applicable Information
Visibility In Pacific Northwest	Just Below The Southern Horizon In July
Best Times To View	Just Below The Southern Horizon In July
Right Ascension	15h 12m 13.6119s to  16h 36m 08.3235s
Declination	−42.27° to −60.44°
Area	165 square degrees
Main Stars	4
Brightest Object	γ2 Nor
Meteor showers	Gamma Normids
Messier objects	0
Neighboring Constellations	Ara, Lupus, Circinus, Triangulum Australe, Scorpius

History

Norma was introduced in 1751–52 by Nicolas-Louis de Lacaille with the French name l’Équerre et la Règle, “the Square and Rule”,^[1] after he had observed and catalogued 10,000 southern stars during a two-year stay at the Cape of Good Hope. During this time, Lacaille would document 14 new constellations in an area that was uncharted to Europeans since the sky was not visible in Europe. As part of his work, Lacaille portrayed the constellations of Norma, as a set square and ruler in a set of draughtsman instruments, in his 1756 map of the southern stars. The original name of the constellation was shortened and Latinized in 1763.

Stars

Due to its location on the Milky Way, this constellation contains many deep-sky objects such as star clusters, including eight open clusters visible through binoculars. NGC 6087 is the brightest of the open clusters in Norma with a magnitude of 5.4, with fainter open clusters including NGC 6134, NGC 6167, NGC 6115, NGC 6031, and NGC 5999.

Another interesting objects include Shapley 1, a planetary nebula better known as the Fine-Ring Nebula, which appears ring shape and is oriented towards Earth.. Appearing ring-shaped, it is thought that it actually is cylindrical and oriented directly at Earth. Abell 3627 is known as the Norma Cluster, which is one of the most massive galaxy clusters known to exist, at ten times the average cluster mass.

Make sure to check out other articles on the site, including a brief introduction to constellations, other constellation articles, and more!

Sources:

1 = Ridpath, Ian. “Lacaille’s Southern Planisphere of 1756”. Star Tales. Self-published. Retrieved 19 March 2015.