Ross 640

light-years

Catalog numbers:
     Gliese (Gl) 626.2, Giclas (G) 180-57, Luyten Half-Second (LHS) 3200, Eggen/Greenstein white dwarf (EG) 119, Ross 640
Arity: singular
Right Ascension and Declination: 16h26m40s, +36°52'12" (epoch 1950.0)
Distance from Sol: 51.0 light-years (15.6 parsecs)
Standard error in distance: 5.1852%
Source for distance: Gliese
Celestial (X,Y,Z) coordinates in ly: -16.1, -37.4, 30.6
Galactic (X,Y,Z) coordinates in ly: 19.0, 31.7, 35.1
Proper motion: 0.864 arcsec/yr (326.4° from north)
Radial Velocity: 24 km/sec
Source for proper motion and radial velocity: Gliese
Galactic (U,V,W) velocity components in km/s: -48.2, 17.3, 45.2

What do all these fields mean?


Spectral class: DZA6
Luminosity Class: wd
Apparent visual magnitude: +13.85
Absolute visual magnitude: +12.88
Visual luminosity: 0.00061 x Sol
Color indices: B-V= +0.17, U-B= -0.67
Diameter: 0.014 x Sol
Source for diameter: Apparent Diameters and Absolute Radii of Stars (Fracassini+ 1988)
Comfort Zone (visual): 0.025 A.U.s
Angular size of star in sky in CZ: 0.301443 degrees

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