I/22A Astrographic Catalogue (AC), -02/+04deg (Lacroute+ 1981)
Astrographic Catalogue: Alger zone
Lacroute P., Valbousquet A.
<Bull. Inform. CDS 6 (1974)>
=1974BICDS...6...38L 1974BICDS...6...38L
Valbousquet A.
<Bull. Inform. CDS 13, 2 (1977)>
=1977BICDS..13....2V 1977BICDS..13....2V
Lacroute P.
<Bull. Inform. CDS 21, 2 (1981)>
=1981BICDS..21....2L 1981BICDS..21....2L
ADC_Keywords: Positional data ; Astrographic zones ; Magnitudes, photographic
Description:
The "Carte de Ciel" (or "Astrographic Catalogue") is a catalogue of
star positions and magnitudes, determined on the photographic plates
taken by the normal astrographs which are installed in observatories
of various latitudes, as a world-wide astronomical project (see
Eichhorn, 1974, p279). The catalogue is divided into 22 declination
zones, each of which is assigned to each observatory, e.g., a zone
from +18 to +24 degrees is to Paris observatory.
Each observatory has taken photographs of 2 deg x 2 deg area in and
covering each zone, measured the X,Y coordinates of star images on the
photographic plates, and published the results as the printed
catalogues. The present catalogue is the results of reduction of these
X,Y coordinates into right ascension and declination values, for
declination zones of +05 to +31, by using AGK2/3 catalogue as the
reference.
Data completeness:
Incompletenesses of the data are as follows:
(1) The latter half of the data of zone +04 is missing.
(2) Declination values for negative declination zones have
different expres sions details of which are unknown.
(3) X,Y coordinate values are attached but are different from
those values published by Alger observatory.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
catalog 63 306432 Alger zone -02/+04 degrees
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Byte-by-byte Description of file: catalog
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Bytes Format Units Label Explanations
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1- 3 I3 deg ZONE *[-2/4] plate identifier
4- 7 I4 --- PLATE *[-180/180] plate identifier
8- 11 I4 --- STAR running number of star on the plate
12- 21 I10 mas RAmas [0/1296000000[ right ascension (B1950)
22- 31 I10 mas DEmas [-324000000/324000000] declination (B1950)
32- 36 I5 0.01yr EPOCH [0/20000] plate epoch from 180000
37- 39 I3 dmag mB [-99/999] photographic magnitude
40- 47 I8 0.1um X [-9999999/9999999] X coordinate on the plate
48- 55 I8 0.1um Y [-9999999/9999999] Y coordinate on the plate
56- 58 I3 deg AGK3Z *[0/89]? AGK3 number : zone number
59- 62 I4 --- AGK3N [1/9999]? AGK3 number : star number
63 I1 --- ZERO [0] zero
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Note on ZONE:
declination zone, or the declination of the center of each
astrographic plate
Note on PLATE:
running number of plate in the zone
Note that this number is negative when the zone is negative.
Note on AGK3Z:
No signs on any AGK3 zones.
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See Also:
I/21 : Zones +05 to +31 (Alger zones) (Lacroute and Valbousquet, 1974)
I/154 : Zones -02 to +31 degrees of AC (Roeser, 1990) (RA and DE files)
I/155 : Zones -02 to +31 degrees of AC (Roeser, 1990) (X and Y files)
I/171 : Astrographic Catalog Reference Stars (ACRS) (Corbin+ 1991)
Historical Notes:
* Originally the Paris zone was archived as I/22, and the Alger zone was
included in I/21. However, the data format of Alger zone is different
from others and the data have some incompleteness, and we rearranged
them, separating the Alger zone data as I/22A.
References:
Eichhorn H. (1974): Astrometry of Star Positions, Frederick Unger Publ.
Co., New York.
(End) Koichi Nakajima [CDS] 24-Sep-1993 J.A. Watko [SSDOO/ADC] 18-Jan-1996