CPD (S0): Cape Photographic Durchmusterung (19950102)
FILES:
Name Magnitude range Dec (2000) range #Stars
cpd70.s0 1.3 <= mag <= 7.0 -90 <= Dec < -18 2959
cpd7180.s0 7.1 <= mag <= 8.0 -90 <= Dec < -18 12721
cpd8185.s0 8.1 <= mag <= 8.5 -90 <= Dec < -18 17982
cpd8690.s0 8.6 <= mag <= 9.0 -90 <= Dec < -18 48150
cpd91a.s0 9.1 <= mag <=11.4 -30 < Dec < -18 67370
cpd91b.s0 9.1 <= mag <=11.4 -40 < Dec <= -30 65601
cpd91c.s0 9.1 <= mag <=11.2 -50 < Dec <= -40 87121
cpd91d.s0 9.1 <= mag <=11.2 -60 < Dec <= -50 89484
cpd91e.s0 9.1 <= mag <=11.1 -90 <= Dec <= -60 63426
cpd_nomg.s0 NO MAGNITUDES -90 <= Dec < -18 63
CONTENTS: Cape Photographic Durchmusterung; NSSDC 1984 version (454877 stars)
DATASET: These files compose HyperSky dataset S-22, version 19950102. Availability on HyperSky CD-ROM: Vol. 2 (1995)
DESCRIPTION: These datafiles contain the Cape Photographic Durchmusterung (CPD) star catalog. The CPD (CPD, Gill and Kapteyn 1895-1900) is a photographic survey of southern stars in the declination range -18 deg to -90 degrees. The original goal of the work was to carry out a southern survey similar to those of the "Bonner Durchmusterung" (BD, Argelander 1859-1862) and the Cordoba Durchmusterung (CD, Thome 1892-1932) but using photographic plates to provide a permanent record of the sky at the epoch of observation.
The summary of the positional uncertainties quoted in the third volume of the published catalog gives +/- 0.28 sec (R.A.), +/- 0.044 arcmin (Dec) for zones -18 to -57 degrees, +/- 0.157 sec + 0.0764/cos(delta) sec (R.A.), +/- 0.056 arcmin (Dec.) for zones -58 to -85 degrees, and +/- 0.157 sec + 0.0353/cos(delta) sec (R.A.), +/- 0.0127 arcmin (Dec) for the polar plate where, as explained in the introduction to the third volume, many positions were derived from rectangular coordinates (these are positions reported to 0.1 sec (R.A.) and 0.001 arcmin (Dec) in the -86 to -89 degree zones in the catalog).
The probable error of a photographic magnitude, as determined by combining results for different magnitudes and weighting proportionately according to the numbers of stars in each class of magnitude, is given as +/- 0.055 mag. From an analysis of the faint magnitude limits on the plates discussed in the third volume introduction, the catalog as a whole can be considered complete to photographic magnitude 9.2, but it is stated that it will be found practically complete, in or near the Milky Way, to magnitude 9.5. The total number of stars in the zones -19 to -89 degrees and the total sky area covered result in a mean density of 32.66 stars per square degree, as compared with 15.19 for Argelander's BD, 18.21 for Schoenfeld's SD, and 56.00 for the CD zones -22 through -41 degrees.
The National Space Science Data Center (NSSDC) 1984 machine-readable version of the CD contains the complete catalog, including corrections published in all errata. The machine version contains 454877 records, but only 454875 stars (two stars were later deleted, but their logical records are retained in the file so that the zone counts are not different from the published catalog).
The HyperSky files are based on the version of the catalog available as NASA/GSFC Astronomical Data Center (ADC) catalog #1108.
DATA: The HyperSky datafiles contain the following data from the CPD catalog:
POSITION: Right Ascension and Declination are based on the 1875 catalog values, precessed to equinox 2000. Accuracies are discussed above.
MAG: The photographic magnitudes as provided in the catalog, and discussed above.
TY: not provided; no (spectral) types are given by the CPD.
IDENTIFICATION: The CPD number of the star, in the form +DD NNNN, where DD (+ or -) is the Declination zone number, and NNNN is the assigned number of the star within the Declination zone. A single code letter may be optionally be appended to this number, which may be one of the following:
a The star is a supplemental addition from the errata.
D The star is deleted in the errata (the data are left intact).
COMMENTS: A single comment line will appear only for stars in the file cpd_nomg.s0, where the magnitude was replaced by a code. The code translation appears as the one-word comment "nebula".