Melbourne Observatory 4

light-years

Catalog numbers:
     Gliese (Gl) 667, Henry Draper (HD) 156384, Cordoba Durchmusterung (CD) -34°11626, Hipparcos Input Catalog (HIC) 84709, Smithsonian Astrophysical Observatory (SAO) 208670, UGPMF 433, Hoffleit Bright Star (HR) 6426, Melbourne Observatory (MLO) 4, New Suspected Variable (NSV) 8482
Heavy element abundance: 26% of Sol
Source for heavy element abundance: Strobel [Fe/H] Determinations
Arity: trinary
Right Ascension and Declination: 17h18m57.164s, -34°59'24.25" (epoch 2000.0)
Distance from Sol: 23 light-years (7.0 parsecs)
Standard error in distance: 10.662%
Source for distance: Hipparcos
Celestial (X,Y,Z) coordinates in ly: -3.3, -18, -13
Galactic (X,Y,Z) coordinates in ly: 23, -3.1, 0.3
Proper motion: 1.167 arcsec/yr (99.2° from north)
Source for proper motion: Gliese

What do all these fields mean?

Data for A and B's orbit around one other:
Combined absolute visual magnitude: +6.68
Combined visual luminosity: 0.2 x Sol
Period: 42.09 years
Semimajor Axis: 13 A.U.s
Eccentricity: 0.574
Periastron distance: 5.4 A.U.s
Apastron distance: 20 A.U.s
Year in which periastron occurs: 1933.7
Source for orbit data: W.P. Hirst
As seen from A:
     At periastron, B would appear as magnitude -19.92
     At apastron, B would appear as magnitude -17.09
As seen from B:
     At periastron, A would appear as magnitude -20.83
     At apastron, A would appear as magnitude -18.00

Data for (A-B) and C's orbit around one other:
Combined absolute visual magnitude: +6.66
Combined visual luminosity: 0.2 x Sol
Observed Separation: 213 A.U.s
Year of separation observation: 1889
As seen from (A-B):
     C would appear as magnitude -8.91
As seen from C:
     (A-B) would appear as magnitude -13.25

Data for (A-B) and C's orbit, take 2:
Observed Separation: 215 A.U.s
Year of separation observation: 1948
As seen from (A-B):
     C would appear as magnitude -8.89
As seen from C:
     (A-B) would appear as magnitude -13.23


Component A:
Catalog numbers:
     Luyten Half-Second (LHS) 442
Spectral class: K3
Luminosity Class: V
Apparent visual magnitude: +6.29
Absolute visual magnitude: +7.07
Visual luminosity: 0.1 x Sol
Diameter: 0.9 x Sol
Source for diameter: Apparent Diameters and Absolute Radii of Stars (Fracassini+ 1988)
Comfort Zone (visual): 0.4 A.U.s
Angular size of star in sky in CZ: 1.312281 degrees


Component B:
Catalog numbers:
     Luyten Half-Second (LHS) 442
Proper motion: 1.167 arcsec/yr (99.2° from north)
Radial Velocity: 1 km/sec
Source for proper motion and radial velocity: Gliese
Galactic (U,V,W) velocity components in km/s: 3.8, 16, -35
Spectral class: K5
Luminosity Class: V
Apparent visual magnitude: +7.20
Absolute visual magnitude: +7.98
Visual luminosity: 0.06 x Sol
Comfort Zone (visual): 0.2 A.U.s


Component C:
Catalog numbers:
     Luyten Half-Second (LHS) 443
Right Ascension and Declination: 17h15m34s, -34°56'30" (epoch 1950.0)
Celestial (X,Y,Z) coordinates in ly: -3.6, -18, -13
Galactic (X,Y,Z) coordinates in ly: 22, -3.2, 0.6
Proper motion: 1.18 arcsec/yr (98.3° from north)
Radial Velocity: 0.6 km/sec
Source for proper motion and radial velocity: Gliese
Galactic (U,V,W) velocity components in km/s: 4.0, 17, -35
Spectral class: M2.5
Luminosity Class: V
Apparent visual magnitude: +10.24
Absolute visual magnitude: +11.02
Visual luminosity: 0.003 x Sol
Color indices: B-V= +1.57, U-B= +1.16, R-I= +0.96
Comfort Zone (visual): 0.06 A.U.s

light-years
but not more than light-years away
Data for this star system were most recently updated on 4-April-2001.