Theta Ursae Majoris

light-years
Proper names: Theta Ursae Majoris, 25 Ursae Majoris
Catalog numbers:
     Gliese (Gl) 354, Henry Draper (HD) 82328, Bonner Durchmusterung (BD) +52°1401, Luyten Half-Second (LHS) 270, Hipparcos Input Catalog (HIC) 46853, Smithsonian Astrophysical Observatory (SAO) 27289, Aitken Double Star (ADS) 7420, Fifth Fundamental Catalogue (FK5) 358, Hoffleit Bright Star (HR) 3775, New Suspected Variable (NSV) 4519
Age: 2500 million years
Source for age: B. Edvardsson et al., "Chemical Evolution of the Galactic Disc", A&AP 275
Heavy element abundance: 90% of Sol
Standard error in heavy element abundance: 10%
Source for heavy element abundance: Strobel [Fe/H] Determinations
Arity: the A star is a possible spectroscopic binary
Right Ascension and Declination: 9h32m51.412s, +51°40'38.38" (epoch 2000.0)
Distance from Sol: 43.99 light-years (13.49 parsecs)
Standard error in distance: 0.9881%
Source for distance: Hipparcos
Celestial (X,Y,Z) coordinates in ly: -21.84, 16.33, 34.51
Galactic (X,Y,Z) coordinates in ly: -29.47, 7.573, 31.76
Proper motion: 1.095 arcsec/yr (240.4° from north)
Radial Velocity: 15.3 km/sec
Source for proper motion and radial velocity: Gliese
Galactic (U,V,W) velocity components in km/s: -57.59, -35.35, -23.84

What do all these fields mean?

Data for A and B's orbit around one other:
Combined absolute visual magnitude: +2.52
Combined visual luminosity: 8.548 x Sol
Observed Separation: 68.78 A.U.s
Year of separation observation: 1889
As seen from A:
     B would appear as magnitude -9.23
As seen from B:
     A would appear as magnitude -19.86

Data for A and B's orbit, take 2:
Observed Separation: 55.29 A.U.s
Year of separation observation: 1958
As seen from A:
     B would appear as magnitude -9.71
As seen from B:
     A would appear as magnitude -20.34


Component A:
Spectral class: F6
Luminosity Class: IV
Apparent visual magnitude: +3.17
Absolute visual magnitude: +2.52
Visual luminosity: 8.547 x Sol
Color indices: B-V= +0.46, U-B= +0.02, R-I= +0.16
Diameter: 2.551 x Sol
Source for diameter: Apparent Diameters and Absolute Radii of Stars (Fracassini+ 1988)
Comfort Zone (visual): 2.924 A.U.s
Angular size of star in sky in CZ: 0.465171 degrees


Component B:
Spectral class: M
Luminosity Class: V-VI
Apparent visual magnitude: +13.80
Absolute visual magnitude: +13.15
Visual luminosity: 0.000478 x Sol
Mass: 0.12 x Sol
Diameter: 0.29 x Sol
Source for diameter: Apparent Diameters and Absolute Radii of Stars (Fracassini+ 1988)
Comfort Zone (visual): 0.0219 A.U.s
Orbital period in CZ: 3.40966 days
Tidal index in CZ: 11475.2
Angular size of star in sky in CZ: 7.069816 degrees

light-years
but not more than light-years away
Data for this star system were most recently updated on 12-May-2001.