1073B I/73B Sydney Photographic Cat 20457 Stars, -48 to -54 H Eichhorn W D Googe C F Lukac J K Murphy AJ 88 546 1983 1983AJ.....88..546E Positional data Photographic catalog This catalog is also known as the Sydney Photographic Catalogue -48 to -54 Degrees or SPC and gives positions determined by the plate overlap method from plates taken at the Sydney Observatory in 1964. The catalog was originally planned to fill part of the gap left by the Yale Zone and Cape Photographic Catalogues, although the gap has in the meantime been closed by catalogs prepared at Sydney Observatory (Nicholson 1979, King and Lomb 1983). Data in the catalog include star number (CPD; identifications not complete), source catalog identification (AC zones) and related information, right ascension/declination on the FK4 system (equinox and equator B1950, average epoch 1964.475), photovisual magnitude, and numbers of images and pairs of diffraction spectra used in computing position.

CPDnum Number in Cape Photographic Durchmusterung From Gill and Kapteyn (1897, 1900). The zone sign (always -) is in byte 1, the zone in bytes 2-3, byte 4 is blank, and the number is in bytes 5-9. The identifications are not complete, i.e., existing CPD numbers are not always present. --- Source Source catalog identification A Gill and Hough (1923) B Jackson and Stoy (1955) 1-120 Plates in Cape AC zone -49 deg 121-240 Plates in Cape AC zone -51 deg (Cape 1913-1926) 241-360 Plates in Sydney AC zone -53 deg (Sydney Obs. 1923-1933; see Wood 1971) where each AC zone is covered by 120 plates and 120 or 240 is subtracted to obtain plate numbers in the -51 deg and -53 deg zones, respectively. --- number Star or plate number in the source catalog --- refstar Asterisk (*) means the star served as a reference star. --- RAh Right ascension hours (1950) Given for the mean coordinate system 1950, ostensibly on the system of the FK4, at the average epoch 1964.475 of all plates which provided data. (If higher accuracy epochs are required, Table I of Eichhorn et al. 1983 should be consulted.) h RAm Right ascension minutes (1950) min RAs Right ascension seconds (1950) s DE- Sign of declination (1950) --- DEd Declination degrees (1950) deg DEm Declination minutes (1950) arcmin DEs Declination seconds (1950) arcsec Ptm Photovisual magnitude, taken from existing sources. For AC stars, the magnitudes were computed from data given in the AC and are photographic. Magnitudes are neither precise nor accurate and are given for reference purposes only. mag o_image Number of measured central images used to calculate the published position. --- o_spect Number of pairs of diffraction spectra used to calculate the published position. The number of individual images measured for computing a published position is the number in byte 51 plus twice the number in byte 53 (see Eichhorn et al. 1983). --- adc.docADC Documentation James E. Gass SSDOO/ADC 1997Jul31Appreciation is expressed to Dr. H. Eichhorn for providing the SPC on tape and for reviewing and commenting on the original ADC document. UNKNOWN UNKNOWN The machine-readable version of the SPC was received on magnetic tape from records with bytes 1-25 blank and many other blanks throughout the records. The records on this tape had been designed specifically for printing the catalog and microfiching rather than for efficient storage and computing. To increase storage efficiency the following modifications were made after checking with the first author to be certain that the changes would be acceptable. 1. Superfluous blanks were removed from throughout the data records, except for a single separator blank between each of the data fields decreasing the logical record length from 104 to 53 bytes. 2. Leading zeros were added to all right ascension and declination fields. I_73B.xml