Gamma Centauri

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Gamma Centauri A/B
Observation data
Epoch J2000
Constellation
(pronunciation)
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
Visual binary orbit
Companion γ Centauri B
Period (P) 83.0 yr
Semimajor axis (a) 0.86"
Eccentricity (e) 0.79
Inclination (i) 114°
Longitude of the node (Ω)
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°