Sydney Southern Star Catalogue

The reference catalogue used was the WL50. The standard error of a position based on four images is 0.10" in either coordinate. A 2.3 magnitude diffraction grating was used to produce side images shifted from the central image in declination.

The stars selected were compiled from the Cape Photographic Catalogue for 1950 (CPC) (Jackson and Stoy 1954-1958), International Reference Stars (IRS) (Scott 1962), Cape Zone Cataloge for 1900 (ZC) (Gill and Hough 1923, Spencer Jones and Jackson 1936), Albany General Catalogue (GC) (Boss 1937) and the Sydney Astrographic Catalogue (AC) (Nangle and Wood 1925-1971). The Sydney AC was used to obtain 3244 supplementary faint stars so that about one star per square degree is in the photographic magnitude range 11.0 to 11.5.

All of the AC stars were given a magnitude of 12.0 to distinguish them as AC stars although they are presumed to be in the stated photographic magnitude range. In the area south of -63.5 deg., only the IRS stars were selected for measurement. This was to give complete plate coverage for the determination of plate constants for the plates centered at -6358.5 deg. 395 IRS stars are included in this zone.

CPC stars and AC stars were selected for measurement between declinations -52deg. and -63.5 deg. Between -51deg. and -52deg., the measuring list was prepared by supplementing the few CPC stars in this area with ZC stars, GC stars, and IRS stars. In general, stars brighter than photographic magnitude 6.0 were excluded and stars brighter than photographic magnitude 8.1 had their first order side images measured as well as the central image, giving three measurements.