2001A&A...374..132L

We present new astrometric and photometric data for 253 visual double stars of the ``intermediate'' class, i.e. with angular separations in the range 1 to 15 arcsec. The multi-colour observations were obtained in 1992-94 as part of the ESO Key Programme ``Visual Double Stars'' performed at La Silla Observatory (Chile). Differential magnitudes and colours have been secured in a systematic way while component magnitudes and colour indices have been determined in the V and I passbands of the Cousins standard system in good photometric conditions only. Internal and mean external errors are smaller than respectively 0.01mag and a few hundreths of a magnitude (typically less than 0.03mag). Relative positions are obtained as a by-product with internal errors of the order of 0.006" in angular separation (corresponding to pixel width x 0.02) and 0.07° in position angle. Final accuracies are thoroughly discussed: we illustrate the overall excellent quality of the data and estimate the quality degradation for angular separations barely larger than the width of the seeing disk.