For double or multiple systems for which one or more components are contained in the Hipparcos observing programme (see fields 2-3), fields 45-50 provide concise information (position angle, separation and magnitude difference, when available) describing the system.
The values given in fields 47-49 refer to the two components specified in field 46. If the entry is a primary component, fields 46 to 49 are blank.
The CCDM and HIC numbers provide the link between the main catalogue and Annex 1. More comprehensive explanations and data on the relevant double and multiple systems, and details of the data contained in these fields, are given in Annex 1.
[]The data given in fields 45-50 are taken from a provisional
version of the `Catalogue of the Components of Doubles and Multiple
Stars' (CCDM, Dommanget et al., in preparation). As explained under
field 31, the `magnitude difference' given in field 49 was computed
from the CCDM, and may not be consistent with data given in field 27
for the separate components.