70 Ophiuchi

light-years
Proper names: 70 Ophiuchi
Catalog numbers:
     Gliese (Gl) 702, Henry Draper (HD) 165341, Hipparcos Input Catalog (HIC) 88601, Smithsonian Astrophysical Observatory (SAO) 123107, Aitken Double Star (ADS) 11046, Hoffleit Bright Star (HR) 6752, Struve (STF) 2272
Age: 500 million years
Source for age: Don C. Barry, "Chromospheric Age Dependence of…", APJ 334
Heavy element abundance: 74% of Sol
Standard error in heavy element abundance: 20%
Source for heavy element abundance: Strobel [Fe/H] Determinations
Arity: there is partial evidence for a third unseen member
Points of interest:
     If orbital data have been interpreted accurately, the suspected third member of this system should have a mass of only about 0.01 x Sol, or about 10 times the mass of Jupiter, which would not be quite massive enough to ignite as a star -- it would be a brown dwarf.

Right Ascension and Declination: 18h5m27.25s, +2°29'58.22" (epoch 2000.0)
Distance from Sol: 16.59 light-years (5.086 parsecs)
Standard error in distance: 0.697%
Source for distance: Hipparcos
Celestial (X,Y,Z) coordinates in ly: 0.394, -16.57, 0.723
Galactic (X,Y,Z) coordinates in ly: 14.08, 8.195, 3.112
Proper motion: 1.135 arcsec/yr (167.1° from north)
Radial Velocity: -6.9 km/sec
Source for proper motion and radial velocity: Gliese
Galactic (U,V,W) velocity components in km/s: 7.503, -19.77, -18.69

What do all these fields mean?

Data for A and B's orbit around one other:
Combined absolute visual magnitude: +5.49
Combined visual luminosity: 0.556 x Sol
Period: 88.13 years
Semimajor Axis: 23.12 A.U.s
Eccentricity: 0.5
Periastron distance: 11.56 A.U.s
Apastron distance: 34.67 A.U.s
Year in which periastron occurs: 1984.05
Source for orbit data: W.D. Heintz
As seen from A:
     At periastron, B would appear as magnitude -18.79
     At apastron, B would appear as magnitude -16.40
As seen from B:
     At periastron, A would appear as magnitude -20.58
     At apastron, A would appear as magnitude -18.19


Component A:
Catalog numbers:
     Luyten Half-Second (LHS) 458
Spectral class: K0e
Luminosity Class: V
Apparent visual magnitude: +4.21
Absolute visual magnitude: +5.68
Visual luminosity: 0.466 x Sol
Color indices: R-I= +0.26
Mass: 0.82 x Sol
Source for mass: Burnham's Celestial Handbook
Diameter: 0.891 x Sol
Source for diameter: Apparent Diameters and Absolute Radii of Stars (Fracassini+ 1988)
Comfort Zone (visual): 0.683 A.U.s
Orbital period in CZ: 227.629 days
Tidal index in CZ: 2.57469
Angular size of star in sky in CZ: 0.695535 degrees


Component B:
Catalog numbers:
     Luyten Half-Second (LHS) 459
Proper motion: 1.135 arcsec/yr (167.1° from north)
Radial Velocity: -10 km/sec
Source for proper motion and radial velocity: Gliese
Galactic (U,V,W) velocity components in km/s: 4.871, -21.30, -19.27
Spectral class: K5e
Luminosity Class: V
Apparent visual magnitude: +6.00
Absolute visual magnitude: +7.47
Visual luminosity: 0.0897 x Sol
Color indices: B-V= +1.15, R-I= +0.45
Mass: 0.6 x Sol
Source for mass: Burnham's Celestial Handbook
Diameter: 0.73 x Sol
Source for diameter: Apparent Diameters and Absolute Radii of Stars (Fracassini+ 1988)
Comfort Zone (visual): 0.299 A.U.s
Orbital period in CZ: 77.2739 days
Tidal index in CZ: 22.3417
Angular size of star in sky in CZ: 1.299557 degrees

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