Beta Ursae Majoris

light-years
Proper names: 48 Ursae Majoris, Merak, Mirak, Beta Ursae Majoris
Catalog numbers:
     Woolley (Wo) 9343, Henry Draper (HD) 95418, Bonner Durchmusterung (BD) +57°1302, Hipparcos Input Catalog (HIC) 53910, Smithsonian Astrophysical Observatory (SAO) 27876, Fifth Fundamental Catalogue (FK5) 416, Hoffleit Bright Star (HR) 4295, New Suspected Variable (NSV) 5053
Heavy element abundance: 603% of Sol
Source for heavy element abundance: Strobel [Fe/H] Determinations
Arity: singular
Right Ascension and Declination: 11h1m50.482s, +56°22'56.65" (epoch 2000.0)
Distance from Sol: 79.4 light-years (24.3 parsecs)
Standard error in distance: 1.4399%
Source for distance: Hipparcos
Celestial (X,Y,Z) coordinates in ly: -42.6, 11.0, 66.1
Galactic (X,Y,Z) coordinates in ly: -38.7, 23.3, 65.3
Proper motion: 0.086 arcsec/yr (69.8° from north)
Radial Velocity: -12 km/sec
Source for proper motion and radial velocity: Gliese
Galactic (U,V,W) velocity components in km/s: 13.4, 2.49, -7.52

What do all these fields mean?


NOTE: This star is actually a close-orbiting binary pair. The data below are for both sub-components of the pair combined.
Spectral class: A1
Luminosity Class: V
Apparent visual magnitude: +2.37
Absolute visual magnitude: +0.43
Visual luminosity: 58.5 x Sol
Color indices: B-V= -0.02, U-B= +0.01
Diameter: 2.88 x Sol
Source for diameter: Apparent Diameters and Absolute Radii of Stars (Fracassini+ 1988)
Comfort Zone (visual): 7.65 A.U.s
Angular size of star in sky in CZ: 0.200665 degrees

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