Luyten 997-21

light-years

Catalog numbers:
     Gliese (Gl) 772, Luyten Half-Second (LHS) 3501, Eggen/Greenstein white dwarf (EG) 135, Luyten (L) 997-21, Luyten Two-Tenth (LTT) 7879, Luyten FT (LFT) 1503, Luyten Palomar (LP) 634-1
Arity: singular
Right Ascension and Declination: 19h53m56s, -1°10'0" (epoch 1950.0)
Distance from Sol: 37.9 light-years (11.6 parsecs)
Standard error in distance: 3.4753%
Source for distance: Gliese
Celestial (X,Y,Z) coordinates in ly: 18.1, -33.3, -0.77
Galactic (X,Y,Z) coordinates in ly: 28.2, 23.3, -9.75
Proper motion: 0.79 arcsec/yr (211.9° from north)
Radial Velocity: 76 km/sec
Source for proper motion and radial velocity: Gliese
Galactic (U,V,W) velocity components in km/s: 84.8, 13.8, -16.8

What do all these fields mean?


Spectral class: DA6
Luminosity Class: wd
Apparent visual magnitude: +13.70
Absolute visual magnitude: +13.38
Visual luminosity: 0.00039 x Sol
Color indices: B-V= +0.28, U-B= -0.60, R-I= -0.06
Diameter: 0.012 x Sol
Source for diameter: Apparent Diameters and Absolute Radii of Stars (Fracassini+ 1988)
Comfort Zone (visual): 0.020 A.U.s
Angular size of star in sky in CZ: 0.324404 degrees

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