Barnard's Star

Proper names: Barnard's Star, Barnard's Runaway Star
Catalog numbers:
     Gliese (Gl) 699, Giclas (G) 140-24, Hipparcos Input Catalog (HIC) 87937, Bonner Durchmusterung (BD) +4°3561a, Luyten Half-Second (LHS) 57, Vyssotsky McCormick (McC) 799, MDSP 910, Luyten FT (LFT) 1385, Luyten Two-Tenth (LTT) 15309
Age: about 10 000 million years
Heavy element abundance: 20% of Sol
Standard error in heavy element abundance: 100%
Source for heavy element abundance: Strobel [Fe/H] Determinations
Arity: singular
Points of interest:
     Besides moving across the terrestrial sky faster than any other star (almost a third of a degree of arc per century!), Barnard's Star, we are certain, has planets.  Although we have never actually seen these planets, wobbles in Barnard's Star's course indicate that it has two invisible companions, one with a mass of 0.7 times that of Jupiter (0.0007 x Sol) orbiting it at 3 Astronomical Units, and one with a mass of 1.15 times that of Jupiter (0.0015 x Sol) orbiting it at 5 A.U.s with an orbital period of 24 years.  However, since this is an old Population II star which formed before the galaxy became enriched with heavy elements, these planets are going to be carbon and metal poor, probably little more than heavy balls of hydrogen and helium.  (One catalog even states that, despite its velocity’s moderate z-component, Barnard's Star actually belongs to the *very* old galactic halo population.)
     The British Interplanetary Society once proposed Project Daedalus, a mission to send an unmanned spacecraft to Barnard's Star using a deuterium/helium-3 nuclear fusion reaction to provide thrust.  Such a mission would require both a larger spacecraft-construction infrastructure, and better hot-fusion technology, than are currently available.

Right Ascension and Declination: 17h57m48.515s, +4°41'35.83" (epoch 2000.0)
Distance from Sol: 5.941 light-years (1.821 parsecs)
Standard error in distance: 0.287%
Source for distance: Hipparcos
Celestial (X,Y,Z) coordinates in ly: -0.0566, -5.920, 0.486
Galactic (X,Y,Z) coordinates in ly: 4.936, 3.001, 1.388
Proper motion: 10.31 arcsec/yr (355.8° from north)
Radial Velocity: -111 km/sec
Source for proper motion and radial velocity: Gliese
Galactic (U,V,W) velocity components in km/s: -141.0, 3.334, 19.00

What do all these fields mean?

Spectral class: M4
Luminosity Class: V
Apparent visual magnitude: +9.54
Absolute visual magnitude: +13.24
Visual luminosity: 0.000441 x Sol
Color indices: B-V= +1.74, U-B= +1.29, R-I= +1.25
Mass: 0.158 x Sol
Source for mass: European Southern Observatory
Diameter: 0.197 x Sol
Source for diameter: European Southern Observatory
Comfort Zone (visual): 0.0210 A.U.s
Orbital period in CZ: 2.79731 days
Tidal index in CZ: 17049
Angular size of star in sky in CZ: 4.988145 degrees
Detected companions: 2
Companion (unnamed I):
     Mass: 0.7 x Jupiter
     Semimajor Axis: 3 A.U.s
Companion (unnamed II):
     Mass: 1.15 x Jupiter
     Period: 24 years
     Semimajor Axis: 5 A.U.s

but not more than light-years away
Data for this star system were most recently updated on 26-April-2003.