CCD photometry and astrometry of visual double stars We present magnitude and color differences as well as separations andposition angles of the component of 30 visual double and multiplesystems with A-type primaries measured by means of a CCD detectorattached to the 61 cm telescope on Cerro Las Campanas. The angularseparation measured using the V filter rho(V) is systematically largerthan the angular separation measured using the B filter rho(B). At least20 percent of them have very similar astrophysical parameters, but thereal separation of their components is larger than 0.01 parsecs. Thatmeans that these stars are not gravitationally bound, but they have acommon origin.
