Aldebaran

light-years
Proper names: Aldebaran, Alpha Tauri, 87 Tauri
Catalog numbers:
     Gliese (Gl) 171.1, Henry Draper (HD) 29139, Bonner Durchmusterung (BD) +16°629, Hipparcos Input Catalog (HIC) 21421, Smithsonian Astrophysical Observatory (SAO) 94027, Aitken Double Star (ADS) 3321, Fifth Fundamental Catalogue (FK5) 168, Hoffleit Bright Star (HR) 1457, Woolley (Wo) 9159
Heavy element abundance: 80% of Sol
Standard error in heavy element abundance: 10%
Source for heavy element abundance: Strobel [Fe/H] Determinations
Arity: quarternary (!)
Right Ascension and Declination: 4h35m55.237s, +16°30'33.39" (epoch 2000.0)
Distance from Sol: 65.1 light-years (20.0 parsecs)
Standard error in distance: 1.8613%
Source for distance: Hipparcos
Celestial (X,Y,Z) coordinates in ly: 22.4, 58.3, 18.5
Galactic (X,Y,Z) coordinates in ly: -61.3, -1.44, -21.9
Proper motion: 0.2 arcsec/yr (161.1° from north)
Radial Velocity: 54.5 km/sec
Source for proper motion and radial velocity: Gliese
Galactic (U,V,W) velocity components in km/s: -48.8, -19.0, -24.2

What do all these fields mean?

Data for A and B's orbit around one other:
Combined absolute visual magnitude: -0.63
Combined visual luminosity: 156 x Sol
Observed Separation: 607 A.U.s
As seen from A:
     B would appear as magnitude -5.66
As seen from B:
     A would appear as magnitude -18.29

Data for C and D's orbit around one other:
Combined spectrum: K V-VI
Combined apparent visual magnitude: +11.20
Combined absolute visual magnitude: +9.70
Combined visual luminosity: 0.011 x Sol
Observed Separation: 33.9 A.U.s

Data for (A-B) and (C-D)'s orbit around one other:
Combined absolute visual magnitude: -0.63
Combined visual luminosity: 156 x Sol
Observed Separation: 2430 A.U.s
As seen from (A-B):
     (C-D) would appear as magnitude -4.95
As seen from (C-D):
     (A-B) would appear as magnitude -15.28


Component A:
Spectral class: K5
Luminosity Class: III
Apparent visual magnitude: +0.87 (increasing to +0.77)
Absolute visual magnitude: -0.63 (increasing to -0.73)
Visual luminosity: 156 x Sol (increasing to 171 x Sol)
Variable type: slow irregular (pulsating variable)
Color indices: B-V= +1.54, U-B= +1.90, R-I= +0.70
Mass: 2.5 x Sol
Source for mass: Hatzes and Cochran, Astrophysical Journal vol. 413 (1993)
Diameter: 51.5 x Sol
Source for diameter: Apparent Diameters and Absolute Radii of Stars (Fracassini+ 1988)
Comfort Zone (visual): 12.5 A.U.s
Orbital period in CZ: 27.9501 years
Tidal index in CZ: 0.001280
Angular size of star in sky in CZ: 2.196243 degrees


Component B:
Spectral class: M2
Luminosity Class: V
Apparent visual magnitude: +13.50
Absolute visual magnitude: +12.00
Visual luminosity: 0.0014 x Sol
Mass: 0.15 x Sol
Diameter: 0.36 x Sol
Source for diameter: Apparent Diameters and Absolute Radii of Stars (Fracassini+ 1988)
Comfort Zone (visual): 0.037 A.U.s
Orbital period in CZ: 6.75791 days
Tidal index in CZ: 2921.16
Angular size of star in sky in CZ: 5.163467 degrees


Component C:
Proper motion: 0.094 arcsec/yr (112.1° from north)
Radial Velocity: 54 km/sec
Source for proper motion and radial velocity: Gliese
Galactic (U,V,W) velocity components in km/s: -52.2, -8.94, -14.0


Component D:
Proper motion: 0.094 arcsec/yr (112.1° from north)
Radial Velocity: 54 km/sec
Source for proper motion and radial velocity: Gliese
Galactic (U,V,W) velocity components in km/s: -52.2, -8.94, -14.0

light-years
but not more than light-years away
Data for this star system were most recently updated on 30-May-2003.