ADC/CDS Standard Document for Catalog:
/catalogs/1/1223/

IMPORTANT NOTICE:

Superseded     Algiers AC Zone Data Reduced to ACRS (-2 to +4)  (Urban+ 1995)
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Algiers AC Zone Data Reduced to ACRS    
   Urban S.E., Jackson E.S., Corbin T.E.
   <unpublished (1995)>
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ADC_Keywords: Astrographic zones; Astrometric data; Combined data; 
              Cross identifications; Finding lists; Historical catalog; 
              Magnitudes, photographic; Photographic catalog; Plate areas; 
              Plate data; Positional data; Regional catalog; Surveys

Abstract:  
  The U.S. Naval Observatory is in the process of making new reductions
  of the Astrographic Catalogue (AC) using a modern reference system, the 
  ACRS, which represents the system of the FK5.
  The data from the Algiers Zone, whose plates are centered between
  declinations -2 and +4 degrees  (eq. 1900), have been analyzed
  for scale, rotation, tilt, coma, magnitude equation, radial
  distortion and distortions introduced by the use of reseaux in the
  Carte du Ciel program.  The result is a positional catalog of over
  199,000 stars on eq. J2000.0, epoch of observation.  The plate were  
  exposed between 1891 and 1912.  For cross-identification purposes,
  all stars have been matched with the Tycho Input Catalog (revised);
  those numbers have been added to each record.

See also:
 Superseded by catalog 1247:
 1247  The AC2000 Catalogue             (Urban+ 1997)
 at URL ftp://adc.astro.umd.edu/pub/adc/archives/catalogs/1/1247


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