Arcturus

light-years
Proper names: Arcturus, Alpha Bo÷tis, 16 Bo÷tis, Alpha Bootis, 16 Bootis
Catalog numbers:
     Gliese (Gl) 541, Henry Draper (HD) 124897, Bonner Durchmusterung (BD) +19░2777, Luyten Half-Second (LHS) 48, Hipparcos Input Catalog (HIC) 69673, Smithsonian Astrophysical Observatory (SAO) 100944, Fifth Fundamental Catalogue (FK5) 526, Hoffleit Bright Star (HR) 5340, New Suspected Variable (NSV) 6603
Heavy element abundance: 34% of Sol
Standard error in heavy element abundance: 7%
Source for heavy element abundance: Strobel [Fe/H] Determinations
Arity: singular
Points of interest:
     Arcturus is a classic example of a Red Giant; a light- to middle-weight star that has passed the end of its main sequence lifetime and is in a transitional period of bloating up and cooling off.  The total amount of time a star can remain in the red giant stage is on the order of a couple million years, which is not nearly enough time for life as we know it to engage in any serious evolution (if Arcturus has any life-bearing planets at all).

Right Ascension and Declination: 14h15m39.677s, +19°10'56.71" (epoch 2000.0)
Distance from Sol: 36.71 light-years (11.25 parsecs)
Standard error in distance: 0.826%
Source for distance: Hipparcos
Celestial (X,Y,Z) coordinates in ly: -28.77, -19.35, 12.06
Galactic (X,Y,Z) coordinates in ly: 12.98, 3.517, 34.16
Proper motion: 2.281 arcsec/yr (208.8° from north)
Radial Velocity: -5 km/sec
Source for proper motion and radial velocity: Gliese
Galactic (U,V,W) velocity components in km/s: 25.69, -119.0, -2.878

What do all these fields mean?


Spectral class: K2pe
Luminosity Class: III
Apparent visual magnitude: -0.05
Absolute visual magnitude: -0.31
Visual luminosity: 115.6 x Sol
Color indices: B-V= +1.20, U-B= +1.26, R-I= +0.47
Mass: 3.4 x Sol
Source for mass: Hatzes and Cochran, Astrophysical Journal vol. 413 (1993)
Diameter: 31.45 x Sol
Source for diameter: Apparent Diameters and Absolute Radii of Stars (Fracassini+ 1988)
Comfort Zone (visual): 10.75 A.U.s
Orbital period in CZ: 19.114 years
Tidal index in CZ: 0.002737
Angular size of star in sky in CZ: 1.559717 degrees

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