2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/9255I analyze several catalogs of known visual and spectroscopic binaries and conclude that a large number of binaries is missing in current catalogs. Samples of the best studied (nearby and bright) stars indicate that the true binary fraction may be as high as 95%. A preliminary analysis indicates that these binaries can a ect the astrometry signicantly.4 pages, 2 figures To be published in: "Astrometry in the Age of the Next Generation of Large Telescopes," ASP Conference Series, 2005, Eds., P. Kenneth Seidelmann and Alice K. B. MonetAstrophysicstext