Alpha(2) Librae

light-years
Proper names: Alpha(2) Librae, 9 Librae, Zuben El Genubi, Alpha Librae, Zubenelgenubi
Catalog numbers:
     Gliese (Gl) 564.1, Henry Draper (HD) 130841, Bonner Durchmusterung (BD) -15°3966, Hipparcos Input Catalog (HIC) 72622, Smithsonian Astrophysical Observatory (SAO) 158840, Fifth Fundamental Catalogue (FK5) 548, Hoffleit Bright Star (HR) 5531, New Suspected Variable (NSV) 6867
Arity: singular
Right Ascension and Declination: 14h50m52.713s, -16°2'30.42" (epoch 2000.0)
Distance from Sol: 77.2 light-years (23.7 parsecs)
Standard error in distance: 2.4249%
Source for distance: Hipparcos
Celestial (X,Y,Z) coordinates in ly: -54.5, -50.3, -21.3
Galactic (X,Y,Z) coordinates in ly: 57.9, -20.1, 47.0
Proper motion: 0.129 arcsec/yr (236.6° from north)
Radial Velocity: -46.7 km/sec
Source for proper motion and radial velocity: Gliese
Galactic (U,V,W) velocity components in km/s: -39.9, -1.47, -28.2

What do all these fields mean?


NOTE: This star is actually a close-orbiting binary pair. The data below are for both sub-components of the pair combined.
Spectral class: A3
Luminosity Class: IV
Apparent visual magnitude: +2.75
Absolute visual magnitude: +0.88
Visual luminosity: 38.9 x Sol
Color indices: B-V= +0.15, U-B= +0.09, R-I= -0.03
Diameter: 2.95 x Sol
Source for diameter: Apparent Diameters and Absolute Radii of Stars (Fracassini+ 1988)
Comfort Zone (visual): 6.23 A.U.s
Angular size of star in sky in CZ: 0.252314 degrees

light-years
but not more than light-years away
Data for this star system were most recently updated on 4-April-2001.