CD (S0): Cordoba Durchmusterung (19950101)
FILES:
Name Magnitude range Dec (2000) range #Stars
cd70.s0 1.0 <= mag <= 7.0 -90 <= Dec < -21 4456
cd7180.s0 7.1 <= mag <= 8.0 -90 <= Dec < -21 12991
cd8185.s0 8.1 <= mag <= 8.5 -90 <= Dec < -21 16746
cd8690.s0 8.6 <= mag <= 9.0 -90 <= Dec < -21 32079
cd91a.s0 9.1 <= mag <=10.0 -25 < Dec < -21 46568
cd91b.s0 9.1 <= mag <=12.0 -30 < Dec <= -25 77292
cd91c.s0 9.1 <= mag <=11.0 -35 < Dec <= -30 79978
cd91d.s0 9.1 <= mag <=10.0 -40 < Dec <= -35 69350
cd91e.s0 9.1 <= mag <=10.8 -45 < Dec <= -40 71551
cd91f.s0 9.1 <= mag <=12.0 -50 < Dec <= -45 68866
cd91g.s0 9.1 <= mag <=12.0 -55 < Dec <= -50 53934
cd91h.s0 9.1 <= mag <=12.0 -60 < Dec <= -55 39091
cd91i.s0 9.1 <= mag <=12.0 -90 <= Dec <= -60 40875
cd_nomag.s0 NO MAGNITUDES -90 <= Dec < -21 182
CONTENTS: Cordoba Durchmusterung; NSSDC 1984 version (613959 stars)
DATASET: These files compose HyperSky dataset S-21, version 19950101. Availability on HyperSky CD-ROM: Vol. 2 (1995)
DESCRIPTION: These datafiles contain the Cordoba Durchmusterung (CD) star catalog. The CD (Thome 1892-1932) is a visual survey of southern stars in declination zones -22 to -89 degrees (equinox 1875), carried out as an extension to the Bonner Durchmusterung (BD) catalogs of Argelander (1859-1862). The survey was performed using techniques similar to those used for the BD, i.e., the stars were cataloged by allowing the telescope to drift along the mean declination of each zone and recording the positions and magnitudes of stars crossing the transit line of the field.
The goal of the survey was to obtain a position and estimated visual magnitude for every star down to 10.0 magnitude inclusive, but the faint limit is confirmed from comparisons with other catalogs to be somewhat below 10. The positional uncertainties quoted in the original publications vary from +/- 0.42 sec and +/- 0.23 arcmin for zones -22 to -32 deg and +/- 0.33 sec, +/- 0.10 arcmin for zones -42 to -51 deg (errors are not given in the published catalogs south of -51 deg, as these were published after Thome's death in 1908), no doubt due to improved observing techniques and equipment, such as the use of a faintly illuminated reticle, for the later work.
The National Space Science Data Center (NSSDC) 1984 machine-readable version of the CD contains the complete catalog, including corrections published in all corrigenda. The machine version contains 613959 records, but only 613953 stars (six 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 ADC catalog #1114.
DATA: The HyperSky datafiles contain the following data from the CD catalog:
POSITION: Right Ascension and Declination are based on the 1875 catalog values, precessed to equinox 2000. Accuracies are discussed above.
MAG: Visual magnitude estimate.
TY: not provided; no (spectral) types are given by the CD.
IDENTIFICATION: The CD 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 corrigenda.
D The star is deleted in the corrigenda (the data are left intact).
COMMENTS: A single comment line will appear only for stars in the file cd_nomag.s0, where the magnitude was replaced by a code. The code translation appears as a one-word comment, which can be one of "nebula", or "variable".