Gamma Centauri, Latinized from γ Centauri, is a

binary star A binary star is a system of two stars that are gravitationally bound to and in orbit around each other. Binary stars in the night sky that are seen as a single object to the naked eye are often resolved using a telescope as separate stars, in ...

system in the

southern Southern may refer to: Businesses * China Southern Airlines, airline based in Guangzhou, China * Southern Airways, defunct US airline * Southern Air, air cargo transportation company based in Norwalk, Connecticut, US * Southern Airways Express, M ...

constellation of

Centaurus Centaurus is a bright constellation in the southern sky. One of the largest constellations, Centaurus was included among the 48 constellations listed by the 2nd-century astronomer Ptolemy, and it remains one of the 88 modern constellations. I ...

. It has the proper name Muhlifain, not to be confused with Muliphein, which is

γ Canis Majoris Gamma Canis Majoris (γ Canis Majoris, abbreviated Gamma CMa, γ CMa), also named Muliphein , is a star in the constellation of Canis Major. It is unclear exactly why this relatively faint star was given the ' gamma' designation, but pos ...

; both names derive from the same Arabic root. The system is visible to the naked eye as a single point of light with a combined

apparent visual magnitude Apparent magnitude () is a measure of the brightness of a star or other astronomical object observed from Earth. An object's apparent magnitude depends on its intrinsic luminosity, its distance from Earth, and any extinction of the object's lig ...

of +2.17; individually they are third-magnitude stars. This system is located at a distance of about from the

Sun The Sun is the star at the center of the Solar System. It is a nearly perfect ball of hot plasma, heated to incandescence by nuclear fusion reactions in its core. The Sun radiates this energy mainly as light, ultraviolet, and infrared rad ...

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 object ...

. In 2000, the pair had an angular separation of 1.217

arcseconds A minute of arc, arcminute (arcmin), arc minute, or minute arc, denoted by the symbol , is a unit of angular measurement equal to of one degree. Since one degree is of a turn (or complete rotation), one minute of arc is of a turn. The na ...

with a

position angle In astronomy, position angle (usually abbreviated PA) is the convention for measuring angles on the sky. The International Astronomical Union defines it as the angle measured relative to the north celestial pole (NCP), turning positive into the ...

of 351.9°. Their positions have been observed since 1897, which is long enough to estimate an

orbital period The orbital period (also revolution period) is the amount of time a given astronomical object takes to complete one orbit around another object. In astronomy, it usually applies to planets or asteroids orbiting the Sun, moons orbiting planets ...

of 84.5 years and a

semimajor axis In geometry, the major axis of an ellipse is its longest diameter: a line segment that runs through the center and both foci, with ends at the two most widely separated points of the perimeter. The semi-major axis (major semiaxis) is the lon ...

of 0.93 arcsecond. At the distance of this system, this is equivalent to a physical separation of about . The combined

stellar classification In astronomy, stellar classification is the classification of stars based on their spectral characteristics. Electromagnetic radiation from the star is analyzed by splitting it with a prism or diffraction grating into a spectrum exhibiting t ...

of the pair is A1IV+; when they are separated out they have individual classes of A1IV and A0IV, suggesting they are A-type

subgiant A subgiant is a star that is brighter than a normal main-sequence star of the same spectral class, but not as bright as giant stars. The term subgiant is applied both to a particular spectral luminosity class and to a stage in the evolution ...

stars in the process of becoming

giants A giant is a being of human appearance, sometimes of prodigious size and strength, common in folklore. Giant(s) or The Giant(s) may also refer to: Mythology and religion *Giants (Greek mythology) *Jötunn, a Germanic term often translated as 'gi ...

. The star

Tau Centauri Tau Centauri, Latinized from τ Centauri, is a solitary star in the southern constellation of Centaurus. It is visible to the naked eye with an apparent visual magnitude of +3.86. The distance to this star, based upon an annual parallax ...

is relatively close to Gamma Centauri, with an estimated separation of . There is a 98% chance that they are co-moving stars.

Etymology

In Chinese astronomy, (), meaning ''Horn (Chinese constellation), Arsenal'', refers to an Asterism (astronomy), asterism consisting of γ Centauri, ζ Centauri, η Centauri, θ Centauri, 2 Centauri, HD 117440, Xi1 Centauri, ξ¹ Centauri, τ Centauri, D Centauri and σ Centauri. Consequently, the Chinese star names, Chinese name for γ Centauri itself is (, en, the Seventh Star of Arsenal). The people of Arrernte people, Aranda and Luritja tribe around Hermannsburg, Northern Territory, Hermannsburg, Central Australia named a quadrangular arrangement comprising this star, Delta Centauri, δ Cen (Ma Wei), Imai (star), δ Cru (Imai) and γ Cru (Gacrux) as ''Iritjinga'' ("The Eagle-hawk").

References

{{DEFAULTSORT:Gamma Centauri A-type subgiants Binary stars Centaurus (constellation) Bayer objects, Centauri, Gamma Durchmusterung objects, BD-48 7597 Henry Draper Catalogue objects, 110304 Hipparcos objects, 061932 Bright Star Catalogue objects, 4819 TIC objects