1910 20160701171655.0 10.1016/0273-1177(91)90479-4 DOI ASTROimport-67 Lampens, P. 1991 Double star CCD astrometry and photometry About 3000 CCD measurements of double stars have been made in one or both filters V and R on the 1-m Jacobus Kapteyn Telescope at La Palma. The stars form part of the Input Catalogue of the astrometric satellite HIPPARCOS, and require both astrometry and photometry in order to facilitate reduction of the HIPPARCOS measurements. The primary components of the binaries have visual magnitudes between 8 and 12 mag, and the apparent separations between components range from 0.5 to 30 arcsec. The difference in the separation obtained with the two filters is discussed and illustrated for 2100 systems: the dependence upon separation and magnitude difference between components is clearly and quantitatively shown. Argue, A. N. Irwin, M. J. Advances in Space Research 11 1991 119-122 http://esoads.eso.org/abs/1991AdSpR..11..119L published in REFERD