CF Ursae Majoris

Catalog numbers:
     Gliese (Gl) 451, Henry Draper (HD) 103095, Bonner Durchmusterung (BD) +38°2285, Giclas (G) 122-51, Luyten Half-Second (LHS) 44, Hipparcos Input Catalog (HIC) 57939, Smithsonian Astrophysical Observatory (SAO) 62738, Fifth Fundamental Catalogue (FK5) 1307, Hoffleit Bright Star (HR) 4550, New Suspected Variable (NSV) 5374, Groombridge (GRB) 1830
Age: 5400 million years
Source for age: Don C. Barry, "Chromospheric Age Dependence of…", APJ 334
Heavy element abundance: 5% of Sol
Standard error in heavy element abundance: 12%
Source for heavy element abundance: Strobel [Fe/H] Determinations
Arity: binary
Points of interest:
     The B star of this system was discovered only after 1980, and as such little information is available about it. Unless it was captured by the A star's gravity while passing near it (which is highly unlikely), the B star formed at the same time out of the same material as the A star and would be just as heavy-element-deficient.
      Worse, according to a 1984 article in the Publications of the Astronomical Society of the Pacific (96:557-558, July 1984; by W. D. Heintz), there is no trace of a second star in this system and the apparent "flare star" activity seen in 1980 may have been superflares occurring on the A star.

Right Ascension and Declination: 11h52m58.767s, +37°43'7.35" (epoch 2000.0)
Distance from Sol: 29.87 light-years (9.157 parsecs)
Standard error in distance: 0.7092%
Source for distance: Hipparcos
Celestial (X,Y,Z) coordinates in ly: -23.61, 0.724, 18.27
Galactic (X,Y,Z) coordinates in ly: -7.879, 1.643, 28.76
Proper motion: 7.053 arcsec/yr (145.4° from north)
Radial Velocity: -99.1 km/sec
Source for proper motion and radial velocity: Gliese
Galactic (U,V,W) velocity components in km/s: 280.8, -156.3, -17.00

What do all these fields mean?

Data for A and B's orbit around one other:
Combined absolute visual magnitude: +6.63
Combined visual luminosity: 0.193 x Sol
Period: 75 years
Standard Error in period: 33%
Semimajor Axis: 13 A.U.s
Eccentricity: 0.6
Periastron distance: 5.2 A.U.s
Apastron distance: 20.8 A.U.s
Source for orbit data: Proximity Zero, 2nd Edition, by Terry Kepner
As seen from A:
     At periastron, B would appear as magnitude -15.80
     At apastron, B would appear as magnitude -12.79
As seen from B:
     At periastron, A would appear as magnitude -21.35
     At apastron, A would appear as magnitude -18.34

Component A:
Spectral class: G8
Luminosity Class: VI
Apparent visual magnitude: +6.45
Absolute visual magnitude: +6.64
Visual luminosity: 0.192 x Sol
Color indices: B-V= +0.75, U-B= +0.17, R-I= +0.29
Diameter: 0.64 x Sol
Source for diameter: Apparent Diameters and Absolute Radii of Stars (Fracassini+ 1988)
Comfort Zone (visual): 0.438 A.U.s
Angular size of star in sky in CZ: 0.778533 degrees

Component B:
Proper names: CF Ursae Majoris
Spectral class: M
Luminosity Class: V-VI
Apparent visual magnitude: +12.00
Absolute visual magnitude: +12.19
Visual luminosity: 0.00116 x Sol
Variable type: UV Ceti flare star (eruptive variable)
Comfort Zone (visual): 0.0340 A.U.s

Data for this star system were most recently updated on 1-July-2003.