Centaurus: The Horseman in the Sky

Centaurus is one of the largest and brightest constellations in the sky. It is a southern spring constellation that is best seen below the Equator. It is visible in portions of the southern United States, however, below the 30th parallel north, which intersects Jacksonville, Florida and Austin, Texas.

In addition to being one of 88 official modern constellations, Centaurus was also among the 48 ancient constellations listed by Second Century astronomer Ptolemy. It is said to represent the shape of a centaur, a mythological creature made up of a horse’s legs and body with a man’s torso, arms, and head.

Centaurus is one of two centaur-shaped constellations. The other is the zodiac sign Sagittarius. While Sagittarius is said to represent the learned centaur, Chiron, who served as tutor to such heroes as Hercules, Theseus, and Jason (of the Argonauts fame), though, Centaurus is simply a generic centaur.

The constellation contains 69 stars, including 10 very bright ones. Its centaur-shape is made up of 11 stars. Two of them are “first magnitude stars,” which means they are among the brightest in the sky. These are Alpha Centauri, the fourth brightest star in the sky, and Hadar.

There are also a few deep sky objects of note visible within Centaurus, including Omega Centauri (NGC 5139), notable for being the brightest and largest globular cluster in the Milky Way, and two galaxies, Centaurus A (NGC 5128) and Galaxy ESO 325.

The constellation is also home to three annual meteor showers: Alpha Centaurids, Omicron Centaurids, and Theta Centaurids. Nearby constellations include Antlia, Carina, Circinus, , Crux, Hydra, Libra, Lupus, Musca, and Vela.