Centaurus

Centaurus

Constellation
List of stars in Centaurus
Abbreviation	Cen
Genitive	Centauri
Pronunciation	/sɛnˈtɔrəs/, genitive /sɛnˈtɔraɪ/
Symbolism	the Centaur
Right ascension	13
Declination	−50
Area	1060 sq. deg. (9th)
Main stars	11
Bayer/Flamsteed stars	69
Stars with known planets	9
Bright stars	9
Nearby stars	15
Brightest star	Alpha Centauri (α Cen) (−0.01m)
Nearest star	Proxima Centauri (α Cen C) (4.22 ly)
Messier objects	0
Meteor showers	Alpha Centaurids Omicron Centaurids Theta Centaurids
Bordering constellations	Antlia Carina Circinus Crux Hydra Libra (corner) Lupus Musca Vela
Visible at latitudes between +25° and −90°. Best visible at 21:00 (9 p.m.) during the month of May.

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.

Notable features

Stars

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."^[1]

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.

History

Mentioned by Eudoxus in the 4th century BC and Aratus in the 3rd century BC, 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 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 1st century AD, Ptolemy catalogued thirty-seven stars in Centaurus.

While Centaurus now has a high southern latitude, at the dawn of civilization it was an equatorial constellation. Precession has been slowly shifting it southward for millennia, and it is now close to its maximal southern declination. Thousands of years from now it will, once again, be at lower latitudes and be visible worldwide.

Mythology

Centaurus has traditionally been identified as a centaur, a mythological creature, half man, half horse. According to the Roman poet Ovid (Fasti v.379), the constellation honors the centaur Chiron, who was tutor to many of the earlier Greek heroes including Heracles (Hercules), Theseus, and Jason, the leader of the Argonauts. This is unusual, as most authorities consider Sagittarius to be the civilized Chiron, while Centaurus represents a more uncouth member of the species. If Centaurus represents Pholus, then in combination with Lupus, the constellation may have formed the basis of the myth of the Erymanthian Boar, one of the Twelve Labours of Heracles.^{[original research?]}

References

• Centaurus, by Chris Dolan
• C.S. Constellations and Stars
• Constellations, by Richard Dibon-Smith
• Ian Ridpath and Wil Tirion (2007). Stars and Planets Guide, Collins, London. ISBN 978-0007251209. Princeton University Press, Princeton. ISBN 978-0691135564.

External links

Wikimedia Commons has media related to: Centaurus

• The Deep Photographic Guide to the Constellations: Centaurus
• Starry Night Photography: Centaurus
• Star Tales – Centaurus

Coordinates: 13^h 00^m 00^s, −50° 00′ 00″