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.
The constellation Norma as it can be seen by the naked eye
The Ant Nebula, Mz 3, viewed with the Hubble Space Telescope
Galaxies of the Norma Cluster (yellow) in a 0.5° x 0.5° field
Ara is a southern constellation between Scorpius, Telescopium, Triangulum Australe, and Norma. It was one of the Greek bulk described by the 2nd-century astronomer Ptolemy, and it remains one of the 88 modern constellations designated by the International Astronomical Union.
Johann Elert Bode's illustration of Ara, from his Uranographia (1801)
The constellation Ara as it can be seen by the naked eye.
IC 4653 galaxy taken by Hubble.