Centaurus

Centaurus is a southern sky constellation depicting a centaur from Greek mythology. It is one of the largest modern constellations by area and lies predominantly in the southern celestial hemisphere, spanning a broad swath of sky with several bright stars. It is bordered by the constellations Hydra, Circinus, Crux, and Vela, and is best observed from latitudes south of about 30 degrees.

Centaurus was introduced by the French astronomer Nicolas-Louis de Lacaille in the 18th century and named after the mythological centaur. In 1930, the International Astronomical Union formally defined its boundaries, a scheme still in use today.

Among its notable stars are Alpha Centauri, the nearest star system to the Sun when Proxima Centauri is included; Alpha Centauri is a triple-star system comprising Alpha Centauri A, Alpha Centauri B, and Proxima Centauri, with Proxima about 4.24 light-years from the Sun and Alpha Centauri AB about 4.37 light-years away. Beta Centauri (Hadar) is another bright star in the pattern, and the asterism's closest-named identifiers include Rigil Kentaurus for Alpha Centauri A and Toliman for Alpha Centauri B.

Centaurus contains notable deep-sky objects such as Omega Centauri (NGC 5139), a massive globular cluster, and Centaurus A (NGC 5128), a peculiar radio galaxy with a prominent dust lane.

Notably for observers in the southern hemisphere, Centaurus is most readily seen in southern summer evenings, when its bright stars rise higher in the sky.