Theta Antliae

Proper names: Theta Antliae
Catalog numbers:
Gliese (Gl) 366.1, Henry Draper (HD) 84367, Cordoba Durchmusterung (CD) -27°6881, Hipparcos Input Catalog (HIC) 47758, Smithsonian Astrophysical Observatory (SAO) 177908, Fifth Fundamental Catalogue (FK5) 366, Hoffleit Bright Star (HR) 3871, Finsen (FIN) 326, Woolley (Wo) 9306
Arity: binary
Points of interest:
The Hipparcos catalog lists a parallax of 8.48 +/- 0.73 milliarcseconds for this system, which would put it between 350 and 420 light-years away. This is at odds with the data in the Gliese catalog, which puts this system much closer.

Right Ascension and Declination: 9h44m12.11s, -27°46'10.3" (epoch 2000.0)
Distance from Sol: 63 light-years (19 parsecs)
Standard error in distance: 14.7541%
Source for distance: Gliese
Celestial (X,Y,Z) coordinates in ly: -46, 31, -29
Galactic (X,Y,Z) coordinates in ly: -9.8, -58, 21
Proper motion: 0.059 arcsec/yr (301.2° from north)
Radial Velocity: 24 km/sec
Source for proper motion and radial velocity: Gliese
Galactic (U,V,W) velocity components in km/s: -9.0, -22, 6.9

What do all these fields mean?

Data for A and B's orbit around one other:
Combined absolute visual magnitude: +3.35
Combined visual luminosity: 4.0 x Sol
Period: 18.32 years
Semimajor Axis: 2.6 A.U.s
Eccentricity: 0.445
Periastron distance: 1.4 A.U.s
Apastron distance: 3.7 A.U.s
Year in which periastron occurs: 1965.75
Source for orbit data: W.D. Heintz
As seen from A:
     At periastron, B would appear as magnitude -26.62
     At apastron, B would appear as magnitude -24.54
As seen from B:
     At periastron, A would appear as magnitude -26.77
     At apastron, A would appear as magnitude -24.69

Component A:
Spectral class: F6
Luminosity Class: V
Apparent visual magnitude: +5.45
Absolute visual magnitude: +4.03
Visual luminosity: 2.1 x Sol
Diameter: 1.06 x Sol
Source for diameter: Apparent Diameters and Absolute Radii of Stars (Fracassini+ 1988)
Comfort Zone (visual): 1.5 A.U.s
Angular size of star in sky in CZ: 0.387364 degrees

Component B:
Spectral class: F8
Luminosity Class: V
Apparent visual magnitude: +5.60
Absolute visual magnitude: +4.18
Visual luminosity: 1.9 x Sol
Comfort Zone (visual): 1.4 A.U.s

Data for this star system were most recently updated on 4-April-2001.