Lampens, P. ; Argue, A. N. ; Irwin, M. J.

published in Journées 1990: Systèmes de Référence Spatio-Temporels, pp. 219-222 (1990)

Abstract: 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 (INCA) of the astrometric satellite HIPPARCOS, and need both astrometry and photometry. The primary components of the binaries have visual magnitudes between 8m and 12m, and the apparent separations between components range from 0″5 to 30″ 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.

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