Gamma Centauri

Gamma Centauri A/B

Observation data Epoch J2000      Equinox J2000
Constellation	Centaurus
Right ascension	12h 41m 31.0s
Declination	−48° 57′ 35″
Apparent magnitude (V)	+2.2 (+2.9/+2.9)
Characteristics
Spectral type	A0III/A0III
U−B color index	−0.01
B−V color index	−0.01
Variable type	none
Astrometry
Radial velocity (Rv)	−6 km/s
Proper motion (μ)	RA: −187.28 mas/yr Dec.: −1.20 mas/yr
Parallax (π)	25.01 ± 1.01 mas
Distance	130.4 ly (40.0 pc)
Absolute magnitude (MV)	−0.8 (−0.1/−0.1)
Details
Mass	2.8 M☉
Radius	? R☉
Luminosity	? L☉
Temperature	9,300 K
Metallicity	?
Rotation	~81 km/s.
Age	? years
Orbit
Companion	γ Centauri B
Period (P)	83.0 yr
Semi-major axis (a)	0.86″
Eccentricity (e)	0.79
Inclination (i)	114°
Longitude of the node (Ω)	2°
Periastron epoch (T)	1931.2
Other designations
Muhlifain, HR 4819, HD 110304, CD−48°7597, SAO 223603, WDS 12415-4858, HIP 61932, GC 17262, CCDM J12415-4858
Database references
SIMBAD	data

Gamma Centauri (γ Cen / γ Centauri) is a star in the constellation Centaurus. It also has the traditional name Muhlifain, not to be confused with Muliphein, which is γ Canis Majoris; both names derive from the same Arabic root.

Gamma Centauri is a double star approximately 130 light years from Earth, which consists of two spectral type A0 stars each of apparent magnitude +2.9. For the resolution of the double star system a telescope of at least 15 centimeters in aperture is necessary. They have an orbital period of 83 years.

Year	Angular separation	Position angle
1990	1.4″	353°
2000	1.0″	347°
2005	0.7″	341°
2010	0.4″	324°