A constellation known not for its stars (the brightest is of fourth magnitude, none has received its own name), but for the objects of the deep sky: namely, celestial bodies that are different from stars, planets, comets or asteroids. Norma, in fact, includes many open clusters and abundant planetary nebulae, even if rather weak. Above all the Ant nebulae, so called for its insectresembling shape.
Norma is the Latin name, often translated into Ruler (instead of the more correct “set square”): when the French astronomer de Lacaille identified the constellation between 1751 and 1752, he baptised it “Level and ruler”, the carpenter’s tools.