This file explains the format used in the new version of Cordoba Durchmusterung.

The text file new_cd.txt has been obtained from the original cd.txt file available in VizieR database as catalog
I/114, as follows: 1) only declinations -22, -23 and -24 are considered, 2) some discrepancies between the digital
and printed versions have been corrected (those changes are reported in the file changes.txt), 3) data found in the
printed catalog of CD have been added (color and double stars), 4) cross-identification data with PPMX catalog
(VizieR I/312) are appended.

Byte-by-byte Description of file: new_cd.txt
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   Bytes Format   Units    Label       Explanations
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   1-  2  A2      ---      ---         [CD] The catalog prefix
   3-  5  I3      deg      zone        The declination zone
   6- 10  I5      ---      num         The number of the star within the zone
      11  A1      ---      suppl      *[a D] star in corrigenda
  12- 15  F4.1    mag      mag        *Estimated visual magnitude
  16- 17  I2      h        RAh         Hours of right ascension, 1875
  18- 19  I2      min      RAm         Minutes of right ascension, 1875
  20- 23  F4.1    s        RAs         Seconds of right ascension, 1875
      24  A1      ---      DE-         [-] Sign of declination
  25- 26  I2      deg      DEd         Degree of declination, 1875
  27- 30  F4.1    arcmin   DEm         Minutes of declination, 1875
      31  A1      ---      dpl        *[D ] Double flag
      32  A1      ---      color      *[C ] Color flag
      33  A1      ---      type       *[012X] Type of identification
  34- 52  A19     ---      star1       PPMX star / main component
  53- 71  A19     ---      star2       PPMX secondary component
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Note on suppl:
   a: star is added in the corrigenda; D: star is deleted in the corrigenda
Note on mag:
   20.0 = neb; 30.0 = var
Note on dpl:
   D = the star is double visually
Note on color:
   C = the star is yellow or red
Note on type:
   0 = star is not cross-identified
   1 = star is cross-identified with one star of PPMX (star1)
   2 = star is cross-identified with two stars of PPMX (star1 and star2)
   X = star is (manually) cross-identified
       bytes 34-71 have the corresponding identification or a comment

See also (VizieR database):
   I/114 : Cordoba Durchmusterung           (Thome 1892-1932)
   I/312 : PPMX Catalog of positions and proper motions   (Roeser+ 2008)

References:
    Thome, J. M. 1892-1932, Cordoba Durchmusterung, Resultados del
      Observatorio Nacional Argentino 16 (1892, Part I: -22 to -32 deg)
    Roeser S., Schilbach E., Schwan H., Kharchenko N.V., Piskunov A.E.,
      Scholz R.-D.,	PPM-Extended, a catalogue of positions and proper
      motions, Astron. Astrophys. 488, 401-408 (2008).
    Severin D. E, Sevilla D. J., Development of a new digital version of
      "Cordoba Durchmusterung" stellar catalog, Revista Académica
      Electrónica de la U.N.R. 1, 2250-2260 (2015).