Sigma Draconis

light-years
Proper names: Sigma Draconis, 61 Draconis
Catalog numbers:
     Gliese (Gl) 764, Henry Draper (HD) 185144, Bonner Durchmusterung (BD) +69°1053, Luyten Half-Second (LHS) 477, Hipparcos Input Catalog (HIC) 96100, Smithsonian Astrophysical Observatory (SAO) 18396, Hoffleit Bright Star (HR) 7462, New Suspected Variable (NSV) 12176
Age: 3300 million years
Source for age: Don C. Barry, "Chromospheric Age Dependence of…", APJ 334
Heavy element abundance: 58% of Sol
Standard error in heavy element abundance: 2%
Source for heavy element abundance: Strobel [Fe/H] Determinations
Arity: singular
Right Ascension and Declination: 19h32m21.65s, +69°39'40.3" (epoch 2000.0)
Distance from Sol: 18.81 light-years (5.767 parsecs)
Standard error in distance: 0.2646%
Source for distance: Hipparcos
Celestial (X,Y,Z) coordinates in ly: 2.564, -6.014, 17.64
Galactic (X,Y,Z) coordinates in ly: -3.451, 17.10, 7.025
Proper motion: 1.822 arcsec/yr (162.0° from north)
Radial Velocity: 28.2 km/sec
Source for proper motion and radial velocity: Gliese
Galactic (U,V,W) velocity components in km/s: 31.05, 44.63, -17.88

What do all these fields mean?


Spectral class: K0
Luminosity Class: V
Apparent visual magnitude: +4.68
Absolute visual magnitude: +5.87
Visual luminosity: 0.390 x Sol
Color indices: B-V= +0.79, U-B= +0.38, R-I= +0.29
Mass: 0.82 x Sol
Diameter: 1.240 x Sol
Source for diameter: Apparent Diameters and Absolute Radii of Stars (Fracassini+ 1988)
Comfort Zone (visual): 0.624 A.U.s
Orbital period in CZ: 198.909 days
Tidal index in CZ: 3.37186
Angular size of star in sky in CZ: 1.058676 degrees

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