Ross 128

Proper names: FI Virginis
Catalog numbers:
     Gliese (Gl) 447, Giclas (G) 10-50, Luyten Half-Second (LHS) 315, Hipparcos Input Catalog (HIC) 57548, Vyssotsky McCormick (McC) 286, Ross 128
Arity: singular
Right Ascension and Declination: 11h47m44.426s, +0°48'16.96" (epoch 2000.0)
Distance from Sol: 10.89 light-years (3.338 parsecs)
Standard error in distance: 0.729%
Source for distance: Hipparcos
Celestial (X,Y,Z) coordinates in ly: -10.87, 0.582, 0.153
Galactic (X,Y,Z) coordinates in ly: 0.149, -5.504, 9.392
Proper motion: 1.348 arcsec/yr (152.0° from north)
Radial Velocity: -31.1 km/sec
Source for proper motion and radial velocity: Gliese
Galactic (U,V,W) velocity components in km/s: 17.45, 5.806, -32.92

What do all these fields mean?

Spectral class: M4n
Luminosity Class: V
Apparent visual magnitude: +11.56 (increasing to +11.06)
Absolute visual magnitude: +13.94 (increasing to +13.44)
Visual luminosity: 0.000231 x Sol (increasing to 0.000365 x Sol)
Variable type: UV Ceti flare star (eruptive variable)
Color indices: B-V= +1.75, U-B= +1.40, R-I= +1.33
Mass: 0.1 x Sol
Diameter: 0.21 x Sol
Comfort Zone (visual): 0.0152 A.U.s
Orbital period in CZ: 2.16117 days
Tidal index in CZ: 28562.8
Angular size of star in sky in CZ: 7.372880 degrees

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