I/108 Cape Photographic Durchmusterung (Gill+ 1895-1900)
Cape Photographic Durchmusterung (CPD)
Gill D., Kapteyn J. C.
<Cape Photographic Durchmusterung, Ann. Cape Obs. 3 (1895, Part I:
zones -18 to -37 degrees); 4 (1897, Part II: zones -38 to -52
degrees); 5 (1900, Part III: zones -53 to -89 degrees)>
ADC_Keywords: Surveys ; Durchmusterungen
Description:
The "Cape Photographic Durchmusterung" (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, see also
Kuestner 1903) and Schoenfeld (1886) and the "Cordoba
Durchmusterung" (CD, Thome 1892-1932) but using photographic plates
which would 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 intro- duction 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.
Introduction:
The complete catalog is contained in the data file, and corrections
published in all errata have been made to the data. 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).
A list of corrections made to the original data as a result of
errata published in the three volumes is presented in cpchg.dat.
No other corrections or changes have been incorporated into the
original data, e.g., from more modern positions and magnitudes
or comparison with other catalogs. The original ADC document
contains the total number of stars in each declination zone and
the number added and deleted in each zone.
Data are present for all stars in the catalog, including some which
have been deleted in the errata; these have been flagged by a "D"
in byte 11 of each respective record, but the records and data have
been left in the machine version in order not to change the star
counts and numerical sequencing and so that the stars appear in the
correct locations if the catalog is sorted by right ascension.
File Summary:
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File Name Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
adc.doc 80 606 The original ADC document
cpd.dat 32 454877 The CPD catalog
cpchg.dat 79 32 Changes from the printed cat.
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Byte-by-byte Description of the file: cpd.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 A2 --- --- [CP] The catalog prefix
3- 5 I3 deg zone [-18/-89] The declination zone
6-10 I5 --- num The number of the star within the zone
11-11 A1 --- suppl *[a-c D] star in corrigenda
12-15 F4.1 mag mag *Estimated photographic 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
24-24 A1 --- DE- [-] Sign of declination
25-26 I2 deg DEd Degree of declination, 1875
27-32 F6.3 arcmin DEm *Minutes of declination, 1875
-------------------------------------------------------------------------------
Note on suppl:
a, b, or c: star is added in the corrigenda; D: star is deleted in
the corrigenda
Note on mag:
20.0 = neb; 30.0 = var
Note on RAs:
precision varies; tenths can be blank
Note on DEm:
Only bytes 27-30 are used in zones north of -86 deg; the complete
field is used for many stars on the polar plate.
-------------------------------------------------------------------------------
Byte-by-byte Description of the file: cpchg.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- zone The CP zone
5- 9 I5 --- num The CP number
10-10 A1 --- n_num [b ] Note on star number
12-14 A3 --- field The field changed
16-21 F6.2 --- old ? The printed value
23-27 A5 --- new ? The corrected value
30-79 A50 --- note Comments
--------------------------------------------------------------------------------
See also:
I/122 : Bonner Durchmusterung (+89 to -01 degrees)
I/119 : Southern part "Suedlicher Durchmusterung" (-02 to -23 degrees)
I/114 : Cordoba Durchmusterung (-22 to -90 degrees)
History:
The data in the machine-readable "Cape Photographic Durchmusterung"
were keypunched directly from the published catalogs. The northern
zones (-18 to -32 degrees and -35 degrees) were punched at Case
Western Reserve University under the direction of B. N. Rappaport,
who initiated the work and used the data as part of a project on
the production of star charts by computer. However, only zones -18
through -26 degrees and -28 degrees had been verified and checked
thoroughly, and some zones had not been completed. Mr. Rappaport
was contacted and volunteered to continue the project and to
oversee the punching and verifying of the remaining zones and those
not verified and checked at Case. These zones were processed by a
commercial firm with funding provided by the National Space Science
Data Center, but all systematic checking of the completed zones was
carried out by Mr. Rappaport on a volunteer basis. The zones were
rechecked for counts and errata corrections, and the data
reformatted to the standard DM catalog structure at the ADC by the
author. The individual zones were then concatenated from disk data
sets to a single magnetic tape file in CPD number order from north
to south. Users should note that, due to corrections inserted from
the errata, the CPD stars are not strictly in right ascension order
within each zone; hence, if the catalog is sorted by right
ascension, e.g., for search purposes, some CPD numbers will become
disordered.
Acknowledgments:
This project owes its completion to the extensive work and striving
for perfection of Barry Rappaport, who supervised the punching of
all data, ran numerous machine and manual checks on completed zones,
and prepared the preliminary tape of the finished catalog. The
quality work of the keypunchers at Case Western Reserve University
and Syntronix, Sherman Oaks, California is also greatly appreciated.
The encouragement and support of the NSSDC Director, James I. Vette,
made the completion of this project possible.
This document is based on the original ADC document prepared by
Wayne H. Warren, Jr.
References:
Argelander, F. 1859-1862, Bonner Durchmusterung des Nordlichen
Himmels, Erste bis dritte sektion, Astronomischen Beobachtungen
auf der Sternwarte de Koniglichen Rhein.
Friedrich-Wilhelm-Universitats zu Bonn, Bands 3-5.
Gill, D. and Kapteyn, J. C. 1895-1900, Cape Photographic
Durchmusterung, Ann. Cape Obs. 3 (1895, Part I: zones -18 to -37
degrees); 4 (1897, Part II: zones -38 to -52 degrees); 5 (1900,
Part III: zones -53 to -89 degrees).
Kuestner, F. 1903, Bonner Durchmusterung des Nordlichen Himmels,
zweite berichtigte Auflage, Bonn Universitats Sternwarte (Bonn:
A. Marcus und E. Weber's Verlag).
Schoenfeld, E. 1886, Bonner Sternverzeichniss, Vierte Sektion,
Astronomische Beobachtungen auf der Sternwarte der Koniglichen
Rheinischen Friedrich- Wilhelms-Universitat zu Bonn 8, Part IV
(Bonn: Adolph Marcus).
Thome, J. M. 1892-1932, Cordoba Durchmusterung, Resultados del
Observatorio Nacional Argentino 16 (1892, Part I: -22 to -32
degrees), 17 (1894, Part II: -32 to -42 degrees), 18 (1900, Part
III: -42 to -52 degrees), 21 (Part I) (1914, Part IV, -52 to -62
degrees), 21 (Part II) (1932, Part V: -62 to -90 degrees).
(End) Nancy G. Roman [NSSDC/ADC] 12-Nov-1994