Ophiuchus is a large constellation straddling the celestial equator. Its name is from the Greek Ὀφιοῦχος (Ophioukhos, "serpent-bearer"), and it is commonly represented as a man grasping a snake. The serpent is represented by the constellation Serpens. Ophiuchus was one of the 48 constellations listed by the 2nd-century astronomer Ptolemy, and it remains one of the 88 modern constellations. It was formerly referred to as Serpentarius (/sɜːrpənˈtɛəriəs/) and Anguitenens.