The Magellanic Catalogue of Stars (MACS).

We have compiled the Magellanic Catalogue of Stars (MACS), a catalogue of positions for 243 561 stars covering large areas around the Large and Small Magellanic Cloud (LMC and SMC). The positions have been measured using ESO Schmidt plates and refer to the FK5 system via the PPM catalogue. A comparison of positions from different plates shows internal errors at a level of 0.15" to 0.23". The positional accuracy is estimated to be better than 0.5" per coordinate for 99% of the stars. The limiting magnitude of the MACS is B<=16.3mag , but the catalogue is not complete: only those stars are included which are undisturbed by close neighbours as verified by visual screening in order to obtain a clean astrometric reference. We introduce for the MACS a nomenclature and numbering system in accord with IAU rules based on position, leaving the possibility to add further stars without upsetting the numbering system. The catalogue is available via the Centre des Donnees Strasbourg (CDS).