Centaurus is a bright constellation in the southern sky. One of the largest constellations in the sky, Centaurus was included among the 48 constellations listed by the 2nd century astronomer Ptolemy, and it remains one of the 88 modern constellations.
Centaurus contains the Alpha Centauri system, a triple star system consisting of a bright binary star to which the much fainter red dwarf Proxima Centauri is gravitationally bound; Proxima is the nearest known star to the Sun.
In addition to Alpha Centauri (the 4th brightest star in the sky), a second first magnitude star, Hadar, is part of Centaurus.
One of the stars in Centaurus (BPM 37093) is a white dwarf whose carbon atoms are thought to have formed a crystalline structure. Since diamond also consists of carbon arranged in a crystalline lattice (though of a different configuration), scientists have nicknamed this star "Lucy" after the Beatles song "Lucy in the Sky with Diamonds."
Deep sky objects
Centaurus contains ω Centauri (NGC 5139) which, despite being the constellation's "omega" listing, is the brightest globular cluster and largest of its kind in the Milky Way.
The nearby lenticular galaxy, radio source Centaurus A (NGC 5128) and Galaxy ESO 325-G004 is located in the area of Centaurus.
Mentioned by Eudoxus in the 4th century BCE and Aratus in the 3rd century BCE, Centaurus is an ancient constellation. Large as it is now, in earliest times it was even larger, as the constellation Lupus was a sectional asterism within Centaurus as an unspecified animal, possibly a wolf, considered to be either in the centaur's grasp or impaled on its spear. The Southern Cross, which now is pictured as overlaying the centaur's lower hind legs, was also originally a mere asterism formed of the stars composing those legs. Additionally, what is now the minor constellation Circinus was then just random stars under the centaur's front hooves. In the 2nd century AD, Claudius Ptolemy catalogued thirty-seven stars in Centaurus.
Full article ▸