Theta Centauri or θ Centauri, officially named Menkent (), is a single

star A star is an astronomical object comprising a luminous spheroid of plasma (physics), plasma held together by its gravity. The List of nearest stars and brown dwarfs, nearest star to Earth is the Sun. Many other stars are visible to the naked ...

in the southern

constellation A constellation is an area on the celestial sphere in which a group of visible stars forms Asterism (astronomy), a perceived pattern or outline, typically representing an animal, mythological subject, or inanimate object. The origins of the e ...

of Centaurus, the

centaur A centaur ( ; grc, κένταυρος, kéntauros; ), or occasionally hippocentaur, is a creature from Greek mythology with the upper body of a human and the lower body and legs of a horse. Centaurs are thought of in many Greek myths as being ...

. With an apparent visual magnitude of +2.06, it is the fourth-brightest member of the constellation. Based on

parallax Parallax is a displacement or difference in the apparent position of an object viewed along two different lines of sight and is measured by the angle or semi-angle of inclination between those two lines. Due to foreshortening, nearby objects ...

measurements obtained during the

Hipparcos ''Hipparcos'' was a scientific satellite of the European Space Agency (ESA), launched in 1989 and operated until 1993. It was the first space experiment devoted to precision astrometry, the accurate measurement of the positions of celestial obj ...

mission, it is about distant from the Sun. It has a relatively high

proper motion Proper motion is the astrometric measure of the observed changes in the apparent places of stars or other celestial objects in the sky, as seen from the center of mass of the Solar System, compared to the abstract background of the more dista ...

, traversing the

celestial sphere In astronomy and navigation, the celestial sphere is an abstract sphere that has an arbitrarily large radius and is concentric to Earth. All objects in the sky can be conceived as being projected upon the inner surface of the celestial sphere, ...

at the rate of .

Nomenclature

''θ Centauri'', Latinised to ''Theta Centauri'', is the star's

Bayer designation A Bayer designation is a stellar designation in which a specific star is identified by a Greek or Latin letter followed by the genitive form of its parent constellation's Latin name. The original list of Bayer designations contained 1,564 stars. ...

. It bore the traditional name of ''Menkent'' derived from the

Arabic Arabic (, ' ; , ' or ) is a Semitic languages, Semitic language spoken primarily across the Arab world.Semitic languages: an international handbook / edited by Stefan Weninger; in collaboration with Geoffrey Khan, Michael P. Streck, Janet C ...

word مَنْكِب‎ (mankib)for "shoulder" (of the Centaur), apparently blended with a shortened form of "kentaurus" (centaur). In 2016, the

International Astronomical Union The International Astronomical Union (IAU; french: link=yes, Union astronomique internationale, UAI) is a nongovernmental organisation with the objective of advancing astronomy in all aspects, including promoting astronomical research, outreac ...

organized a

Working Group on Star Names The International Astronomical Union (IAU) established a Working Group on Star Names (WGSN) in May 2016 to catalog and standardize proper names for stars for the international astronomical community. It operates under Division C – Education ...

(WGSN) to catalog and standardize proper names for stars. The WGSN approved the name ''Menkent'' for this star on 21 August 2016 and it is now so included in the List of IAU-approved Star Names. In

Chinese Chinese can refer to: * Something related to China * Chinese people, people of Chinese nationality, citizenship, and/or ethnicity **''Zhonghua minzu'', the supra-ethnic concept of the Chinese nation ** List of ethnic groups in China, people of va ...

, (), meaning ''

arsenal An arsenal is a place where arms and ammunition are made, maintained and repaired, stored, or issued, in any combination, whether privately or publicly owned. Arsenal and armoury (British English) or armory (American English) are mostly ...

'', refers to an asterism consisting of Theta Centauri,

Zeta Centauri Zeta Centauri, Latinized from ζ Centauri, is a binary star system in the southern constellation of Centaurus. It has the proper name Alnair , from the Arabic ''Nayyir Baṭan Qanṭūris'' (نير بطن قنطورس), meaning "The B ...

, Eta Centauri, 2 Centauri, HD 117440, Xi1 Centauri, Xi¹ Centauri, Gamma Centauri, Tau Centauri, D Centauri and Sigma Centauri. Consequently, the Chinese star names, Chinese name for Theta Centauri itself is (, en, the Third Star of Arsenal).香港太空館 - 研究資源 - 亮星中英對照表
, Hong Kong Space Museum. Accessed on line November 23, 2010.

Properties

This is an stellar evolution, evolved giant star with a stellar classification of K0 III and 1.27 times the mass of the Sun. The interferometry-measured angular diameter of this star, after correcting for limb darkening, is , which, at its estimated distance, equates to a physical radius of about 10.6 times the Solar radius, radius of the Sun. The stellar atmosphere, outer envelope has an effective temperature of 4,980 Kelvin, K, giving it the orange-hued glow of a cool, K-type star. Soft X-ray emission has been detected from this star, which has an estimated X-ray luminosity of .

References

{{DEFAULTSORT:Theta Centauri K-type giants Centaurus (constellation) Bayer objects, Centauri, Theta Durchmusterung objects Flamsteed objects, Centauri, 5 Gliese and GJ objects, 0539 Henry Draper Catalogue objects, 123139 Hipparcos objects, 068933 Bright Star Catalogue objects, 5288 Stars with proper names, Menkent