ニコラ・ルイ・ド・ラカーユ
Caelum is a faint constellation in the southern sky, introduced in the 1750s by Nicolas Louis de Lacaille and counted among the 88 modern constellations. Its name means “"chisel"” in Latin, and it was formerly known as Caelum Sculptorium (“"the engravers’ chisel"”); It is a rare word, unrelated to the far more common Latin "caelum", meaning “sky, heaven, atmosphere”. It is the eighth-smallest constellation, and subtends a solid angle of around 0.038 steradians, just less than that of Corona Australis.