Alpha Comae Berenices

light-years
Proper names: Alpha Comae Berenices, 42 Comae Berenices
Catalog numbers:
     Gliese (Gl) 501, Bonner Durchmusterung (BD) +18°2697, Hipparcos Input Catalog (HIC) 64241, Smithsonian Astrophysical Observatory (SAO) 100443, Aitken Double Star (ADS) 8804, Struve (STF) 1728, New Suspected Variable (NSV) 6116
Arity: binary
Right Ascension and Declination: 13h9m59.317s, +17°31'46.29" (epoch 2000.0)
Distance from Sol: 63.1 light-years (19.3 parsecs)
Standard error in distance: 9.9303%
Source for distance: Gliese
Celestial (X,Y,Z) coordinates in ly: -57.4, -18.1, 19.0
Galactic (X,Y,Z) coordinates in ly: 10.5, -5.98, 61.9
Proper motion: 0.45 arcsec/yr (288.8° from north)
Radial Velocity: -11.6 km/sec
Source for proper motion and radial velocity: Gliese
Galactic (U,V,W) velocity components in km/s: -41.1, -10.7, -5.92

What do all these fields mean?

Data for A and B's orbit around one other:
Combined absolute visual magnitude: +2.89
Combined visual luminosity: 6.11 x Sol
Period: 25.87 years
Semimajor Axis: 12.8 A.U.s
Eccentricity: 0.5
Periastron distance: 6.40 A.U.s
Apastron distance: 19.2 A.U.s
Year in which periastron occurs: 1911.65
Source for orbit data: H. Haffner
As seen from A:
     At periastron, B would appear as magnitude -23.80
     At apastron, B would appear as magnitude -21.42
As seen from B:
     At periastron, A would appear as magnitude -23.99
     At apastron, A would appear as magnitude -21.61


Component A:
NOTE: This star is actually a close-orbiting binary pair. The data below are for both sub-components of the pair combined.
Catalog numbers:
     Henry Draper (HD) 114378, Hoffleit Bright Star (HR) 4968
Spectral class: F5
Luminosity Class: V
Apparent visual magnitude: +4.98
Absolute visual magnitude: +3.55
Visual luminosity: 3.32 x Sol
Mass: 1.5 x Sol
Diameter: 2.08 x Sol
Source for diameter: Apparent Diameters and Absolute Radii of Stars (Fracassini+ 1988)
Comfort Zone (visual): 1.82 A.U.s
Orbital period in CZ: 2.00788 years
Tidal index in CZ: 0.248041
Angular size of star in sky in CZ: 0.608289 degrees


Component B:
Catalog numbers:
     Henry Draper (HD) 114379, Hoffleit Bright Star (HR) 4969
Proper motion: 0.45 arcsec/yr (288.8° from north)
Radial Velocity: -27.7 km/sec
Source for proper motion and radial velocity: Gliese
Galactic (U,V,W) velocity components in km/s: -43.7, -9.16, -21.7
Spectral class: F5
Luminosity Class: V
Apparent visual magnitude: +5.17
Absolute visual magnitude: +3.74
Visual luminosity: 2.79 x Sol
Mass: 1.5 x Sol
Diameter: 1.21 x Sol
Source for diameter: Apparent Diameters and Absolute Radii of Stars (Fracassini+ 1988)
Comfort Zone (visual): 1.67 A.U.s
Orbital period in CZ: 1.7609 years
Tidal index in CZ: 0.3225
Angular size of star in sky in CZ: 0.386440 degrees

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