Precise equatorial coordinates of double and multiple systems - an astronomical support to the HIPPARCOS mission

In this work we report on the determination of precise positions of 623 double and multiple stars (126 of which are newly discovered systems) obtained from the measurement of 39 plates taken at both the European Southern Observatory (ESO) and the Astronomical Observatory of Torino (AOT) during the period 1984-87. Those positions will be used to update the Catalogue de Composantes d'etoiles Doubles et Multiples (CCDM) and, consequently, the Input Catalogue of the Hipparcos mission, as the CCDM, established on the basis of the Index (1976,5), is the reference source for the known double and multiple stars that appear on the Hipparcos list. Several visual doubles on the list presented here are within those included in the final observing program of the Hipparcos astrometric mission.