Ophiuchus is a large constellation straddling the celestial equator. Its name comes from the Ancient Greek ὀφιοῦχος (ophioûkhos), meaning "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. An old alternative name for the constellation was Serpentarius.
Rho Ophiuchi, shown with a surrounding bluish cloud slightly above a pentagon of stars in Scorpius, with the main band of the Milky Way much further to the left
The constellation Ophiuchus as it can be seen by naked eye
Infrared light view of Rho Ophiuchi molecular cloud complex from NASA
Photo from Rogelio Bernal Andreo of the Rho Ophiuchi molecular cloud complex
Serpens is a constellation in the northern celestial hemisphere. One of the 48 constellations listed by the 2nd-century astronomer Ptolemy, it remains one of the 88 modern constellations designated by the International Astronomical Union. It is unique among the modern constellations in being split into two non-contiguous parts, Serpens Caput to the west and Serpens Cauda to the east. Between these two halves lies the constellation of Ophiuchus, the "Serpent-Bearer". In figurative representations, the body of the serpent is represented as passing behind Ophiuchus between Mu Serpentis in Serpens Caput and Nu Serpentis in Serpens Cauda.
Serpens held by Ophiuchus, as depicted in Urania's Mirror, a set of constellation cards published in London c. 1825. Above the tail of the serpent is the now-obsolete constellation Taurus Poniatovii while below it is Scutum
The constellation Serpens (Caput) as it can be seen by the naked eye
The constellation Serpens (Cauda) as it can be seen by the naked eye
Messier 5, a globular cluster that can be seen with the naked eye under good conditions
