Glen

A comment. The "Hipparcos Input Catalogue" as a source of double stars as referenced is also incorporated into the WDS Catalogue.

Unlike all other sources, the data in the WDS and the 6th Orbit catalogue is continuously updated - everyday in fact.

The Hipparcos satellite data is also flawed, mainly because those between about 2 arcsec and 0.8 arcsec are missing from the list. This was because of the design of the satellite itself, simply caused by the interferometric techniques employed.

"Another source is:
Hipparcos Input Catalogue, Version 2 (Turon+ 1993)
Double and Multiple System Components (32290 rows)
http://cdsweb.u-strasbg.fr/viz-bin/VizieR?-source=I/196

Furthermore, much of the data is actually centred around 1991 - now more than 15 years ago!