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Description
The introduction to this catalogue has been the subject of a publication in the "Communications de l'Observatoire Royal de Belgique" (Serie A, number 115). Detailed are: its origins, its aims, its realization, the search of identifiers, the compilation of astrometric data and the related problems as well as the fundamental ties between the CCDM and the HIPPARCOS INPUT CATALOGUE (HIC). It also contains a complete bibliography of the referred papers. The contents of the general catalogue (63,463 systems) is also described as well as the conditions of its availability to the astronomical community and the projects underway for the next edition. For all these items, the user is invited to refer to this publication because hereafter only the format and the contents of the catalogue follow. To identify the systems and their components, we adopted the clever numbering process of the authors of the INDEX consisting in combining the right ascension and declination, respectively limited to 0.1 minute of time and to 1 minute of arc. In order to distinguish the CCDM numbers from the INDEX numbers - in addition to their different equinox: 2000 for the CCDM and 1900 for the INDEX - we adopted the signs + and - instead of the letters N and S for separating the coordinates. Consequently, in the INDEX and in the CCDM, one entry is devoted to a same system but the contrary to the INDEX, where a sub-entry is assigned to each group of two components, whatever the multiplicity of the system may be, the CCDM allows one sub-entry and thus one record per component. The present edition contains only the 34,031 systems (table below, part I) for which an accurate position has been found for at least one component. The catalogue extends thus much over the sample of the somewhat 14,000 systems finally retained for the HIPPARCOS INPUT CATALOGUE and assembled in its Annex 1.
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