A constellation of the equatorial region of the sky, representing a large snake. It is unique in being split into two halves, which lie on opposite sides of Ophiuchus: Serpens Caput, the serpent's head, which is the larger half; and Serpens Cauda, the serpent's tail. The two are regarded as a single constellation. The brightest star is Alpha Serpentis (Unukalhai), magnitude 2.6. M5 is a 6th-magnitude globular cluster, and M16 is a 6th-magnitude star cluster in the Eagle Nebula.
Subjects: Astronomy and Astrophysics.