Hello Kevin,

from "more info" you will get the following information in the double star section
for Antares:

Comments from the Fifth Catalog of Orbits of Visual Binary Stars:
WDS identifier: 16294-2626
Discoverer identifier: GNT 1
ADS (Aitken Double Star) number: 10074
HD: 148478
Magnitude of first component: 0.96
Magnitude of second component: 5.4
Orbital period: 878. years
Semimajor axis: 2.90 arcseconds
Eccentricity: 0.10
!Year PA Sep Year PA Sep Year PA Sep(")
---- -- --- ---- -- --- ---- -- ---
2000.0 273.7 2.59 2050.0 273.7 1.88 2100.0 273.7 0.970
2010.0 273.7 2.47 2060.0 273.7 1.71 2110.0 273.7 0.771
2020.0 273.7 2.34 2070.0 273.7 1.54 2120.0 273.7 0.568
2030.0 273.7 2.19 2080.0 273.7 1.35 2130.0 273.7 0.362
2040.0 273.7 2.04 2090.0 273.7 1.16 2140.0 273.7 0.154

> I am running April 7 2008 version on both my desktop and laptop.
> The desktop shows 2 components to Antares. They have a separation of
> about 2.5 arcsecond, but are both given the same magnitude. Is one is
> the companion and if so, which one? The laptop shows only one star, why?.

The PA is given from the brighter star which is the east one (following star).
Perhaps you have different datasets on both computers (i.e. no double stars on
the laptop).

Clear skies
Bernd


Bernd Brinkmann

Sternwarte Herne, MPC code A18
Herne, Germany

e-mail: info@...
http://www.sternwarte-herne.de