Alpha Persei

Proper names: Alpha Persei, Mirfak, Mirphak, Marfak, Alchemb, Algenib, 33 Persei
Catalog numbers:
Hoffleit Bright Star (HR) 1017, Bonner Durchmusterung (BD) +49°917, Henry Draper (HD) 20902, Smithsonian Astrophysical Observatory (SAO) 38787, Fifth Fundamental Catalogue (FK5) 120, New Suspected Variable (NSV) 1125
Arity: binary
Right Ascension and Declination: 3h24m19.365s, +49°51'40.34" (epoch 2000.0)
Distance from Sol: 592 light-years (182 parsecs)
Standard error in distance: 10.7%
Source for distance: Hipparcos
Celestial (X,Y,Z) coordinates in ly: 240, 297, 453
Galactic (X,Y,Z) coordinates in ly: -494, 321, -56
Proper motion: 0.0347 arcsec/yr (136.2° from north)
Radial Velocity: -2.3 km/sec
Source for proper motion: Fifth Fundamental Catalogue
Source for radial velocity: Barbier
Galactic (U,V,W) velocity components in km/s: -13, -26, -6.1

What do all these fields mean?

Data for A and B's orbit around one other:
Combined absolute visual magnitude: -4.50
Combined visual luminosity: 5521 x Sol
Observed Separation: 30311 A.U.s
Source for orbit data: Hoffleit Bright Star
As seen from A:
B would appear as magnitude -3.66
As seen from B:
A would appear as magnitude -13.67

Component A:
Catalog numbers:
Hipparcos Input Catalog (HIC) 15863
Spectral class: F5
Luminosity Class: Ib
Apparent visual magnitude: +1.79
Absolute visual magnitude: -4.50
Visual luminosity: 5520 x Sol
Color indices: B-V= +0.48, U-B= +0.37, R-I= +0.33
Diameter: 63 x Sol
Source for diameter: Apparent Diameters and Absolute Radii of Stars (Fracassini+ 1988)
Comfort Zone (visual): 74 A.U.s
Angular size of star in sky in CZ: 0.450699 degrees

Component B:
Apparent visual magnitude: +11.80
Absolute visual magnitude: +5.51
Visual luminosity: 0.5 x Sol
Comfort Zone (visual): 0.7 A.U.s

Data for this star system were most recently updated on 29-September-2001.