Centaurus

Centaurus is a constellation in the southern sky. It is one of the 88 constellations formally defined by the International Astronomical Union (IAU). The name comes from the Centaur of Greek mythology, a creature that is half man and half horse.

Centaurus is among the largest constellations in the sky and is one of the brightest, easily visible from the southern hemisphere of Earth. From far northern latitudes it cannot be seen, or only a small part of the forward section appears above the horizon.

Notable stars

The brightest star is Alpha Centauri, also known as Rigil Kentaurus. It is a multiple star system that includes Proxima Centauri, which is known to be the nearest star to our sun. Beta Centauri (Hadar or Agena) is the second brightest star. The two stars are commonly used to locate the small constellation Crux (Southern Cross).

Deep-sky objects

Within the boundaries of Centaurus lies Omega Centauri, a very large globular cluster that is easily visible. Also located there is the galaxy Centaurus A, a powerful radio source often used in the study of galactic dynamics.

History and use

Centaurus was among the constellations Ptolemy included in his early star catalogue. A portion of the earlier Centaurus region was later designated as the constellation Crux. The modern boundaries rest on the formal definitions adopted in the twentieth century.