MICROMETER MEASUREMENTS OF VISUAL DOUBLE STARS MADE AT THE COTE-DAZUROBSERVATORY

We report the latest of our micrometer measurements of visual double s tars, made with the 50 and 74 cm refractor apertures and 8 and 17.89 m focal length respectively at the Cote D'Azur Observatory (Nice, Franc e). These observations were made in July and September 1997; for previ ous series, see Docobo, Ling, Prieto and Lanchares (1991). The 196 mea surements of 99 double stars are listed in the table in the usual form at: column 1 shows the star's WDS catalogue number (Worley and Douglas s 1996) followed, in the case of multiple star systems, by the letters denoting the components forming the binary; and subsequent columns th e star's name and the ADS catalogue number if available (Aitken 1932), the epoch of the observation, the position angle and angular separati on, the number of nights on which the star was observed with the instr ument used (N for 74 cm, n for 50 cm) and the identification code of t he observer (LIN for Ling, PRI for Prieto). The majority of the observ ations were made with the 50 cm refractor using magnifications of 750x and 938x. In the case of 74 cm refractor the magnification was 1118x. The imprecision of the measurements is estimated as +/-2 degrees for position angles and 15% for angular separation.