I/61B AGK3 Catalogue (Dieckvoss, Heckmann 1975)
AGK3 Catalogue
Dieckvoss W., Heckmann O.
<Hamburg-Bergedorf (1975)>
=1975AGK3..C......0H 1975AGK3..C......0H
=1975QB6.A15........ 1975QB6.A15........
ADC_Keywords: Positional data ; Proper motions ; Magnitudes, photographic
Description:
The AGK3 provides positions and proper motions for stars north of -2.5
degrees. For the most part, it contains the stars in the AGK2 but is
based on newly remeasured reference stars whose positions were reduced
to the FK4 system. A list of 446 AGK2 stars not in the AGK3 and of
three new stars is provided. All plates were taken at the Bergedorf
Observatory. In addition to the positions and proper motions, the
catalog contains magnitudes and spectral types, the epoch of the
observations, the epoch difference between the AGK2 and AGK3, and the
BD numbers.
Introduction:
The AGK3 Star Catalogue of Positions and Proper Motions North of -2.5
Degrees Declination (hereinafter AGK3) was conceived and planned
during discussions between O. Heckmann and D. Brouwer at Hamburg
Observatory following the 1952 International Astronomical Union (IAU)
General Assembly in Rome. It was concluded that an adequate number of
reference stars (AGK3R) should be observed by as many meridian circles
of as many observatories as possible, the revision of FK3, then in
progress (FK4), should define the reference frame, and the same
instruments as used for AGK2 should be used for the observations for
AGK3.
A formal recommendation was adopted through Commission 8 at the 1955
IAU General Assembly in Dublin, with the observatories at Babelsberg,
Bergedorf, Bordeaux, Greenwich, Heidelberg, Nikolajew, Ottawa, Paris,
Pulkovo, Strasbourg and Washington (USNO) to collaborate in the work,
and with F. P. Scott (USNO) to coordinate the meridian circle
observations of AGK3R stars. The completion of the photographic
observations was to be the responsibility of the observatories at
Bergedorf and Bonn, with all plate measurements to be done at the
former. (However, it was finally decided that all plates, even for the
AGK2 Bonn zones, would be taken at Bergedorf.) The plates for AGK3
were secured at Bergedorf between August 1956 and June 1964, with
special precautions (exposures on both sides of the pier) made to
compensate for possible changes in the camera objective.
The two sets of plates were measured at Bergedorf in opposite
directions and averaged to obtain final x,y coordinates. The detailed
procedures for the correction of magnitude-color errors, reduction of
the measures using the AGK3R stars, re-reduction of AGK2 using its
reference catalog AGK2A transformed to the FK4 system, and final
reduction of the AGK3 positions and proper motions, are discussed by
W. Dieckvoss in his technical introduction to the source reference.
Although a more detailed discussion of errors is given by Dieckvoss,
the standard error for one coordinate on one plate as determined from
a limited sample of 110 pairs of plates is ± 0.025" for AGK3.
File Summary:
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FileName Lrecl Records Explanations
-------------------------------------------------------------------------------
ReadMe 80 . This file
agk3doc.txt 79 896 Documentation
agk3.dat 92 183145 Catalog Data
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See also:
I/176 : AGK3U: an updated version of the AGK3 (Bucciarelli+ 1992)
I/69 : AGK3 Catalogue by Right Ascension (Dieckvoss, Heckmann 1975)
I/161 : AGK3R (Smith 1990)
Byte-by-byte Description of file: agk3.dat
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Bytes Format Units Label Explanations
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1 A1 --- AGsign [-+ ]Sign of AGK3 number.
2- 3 I2 --- AGzone AGK3 zone.
4- 7 I4 --- AGnum *AGK3 number
8 A1 --- m_AGnum *[0ab ]Component for duplicates
9- 12 F4.1 mag Pmag Photographic magnitude from AGK2
13- 14 A2 --- Sp *Spectral type
15- 16 I2 h RAh Right ascension hours (1950.0)
17- 18 I2 min RAm Right ascension minutes (1950.0)
19- 24 F6.3 s RAs Right ascension seconds
25 A1 --- DE- [-+ ]Sign of declination (1950.0)
26- 27 I2 deg DEd Declination degrees (1950.0)
28- 29 I2 arcmin DEm Declination minutes
30- 34 F5.2 arcsec DEs Declination seconds
35- 36 I2 --- nobs *Number of photographic observations
37- 41 F5.2 yr Ep-1900 Epoch of AGK3 position minus 1900
42- 47 F6.3 arcsec/yr pmRA *Annual proper motion in right ascension
48- 53 F6.3 arcsec/yr pmDE *Annual proper motion in declination
54- 58 F5.2 yr dEpoch Epoch difference AGK3-AGK2
59- 68 A10 --- BD *Full BD catalog designation
69 A1 --- m_BD *Component of multiple system
70- 71 I2 --- Sum *Sum of discrepancy codes
72- 78 F7.4 s/yr pmsec Annual proper motion in seconds of RA,
computed by dividing by 15cos(delta)
79- 85 F7.4 arcsec dRA *The difference in right ascension in the
sense AGK3 - AGK2modified
86- 92 F7.4 arcsec dDE The difference in declination in the sense
AGK3 - AGK2modified
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Note on AGnum:
AGK3 number in increasing order within each declination zone.
The field is filled with preceding zeros.
Note on m_AGnum:
Component identification where duplicates AGK3 numbers occur.
The lower case letters "a" and "b" may be present.
Note on Sp:
Spectral Type from Henry Draper Catalogue (Cannon and Pickering,
1918-1924), its Extension (Cannon, 1925-1936), Schildt (Yale
Transactions) or determined by A. N. Vyssotsky and collaborators at
the Leander-McCormick Obs.
Note on nobs:
Number of photographic observations used to determine the position.
Single-digit numbers are preceded by a zero.
Note on pmRA, pmDE:
Annual proper motion in right ascension multiplied by cos(delta),
determined by differencing the AGK3 and AGK2 positions and dividing
by the epoch difference. Proper motions are missing for stars new
in AGK3 (see Table 6). If a calculated value of the proper motion
exceeded the field capacity a value of "9999" is given with a "+"
in byte 38.
Proper motion values where transformated in arcsec/yr with erroneous
mas/yr unit indicated in the ReadMe.
Units where corrected on 24/11/2023.
Note on BD:
The full BD identification (see cat. I/122) contains:
bytes 59-60: "BD" or blank
byte 61: Sign of BD zone number
bytes 62-63: BD zone number
bytes 64-68: BD number within zone
Note on m_BD:
Numerical code for identification of a component of a multiple
system: (1 = primary [P]; 2 = secondary [S]; 3 = A; 4 = B; 5 = S1;
6 = S2; 7 = P1; 8 = P2; 9 = C). BD supplemental stars (lower case
letters) are assigned codes but are indistinguishable from A and B
designations because the codes are the same. Since the file format
only allows one byte for the duplicity code, and nine codes are
already used, the distinction cannot be drawn. If it is necessary
to distinguish or identify supplemental stars, the Catalog of BD
Supplemental Stars (Warren and Kress 1980) should be used.
Note on Sum:
Sum of discrepancy codes, calculated as the sum of 2**v (2 to the
power of v), where v = 0 (BD number), 1 (mpg and/or spectral type),
2 (AGK2 right ascension), 3 (AGK2 declination), 4 (AGK3 right
ascension), 5 (AGK3 declination).
Note on dRA:
The residual quantity of the difference in right ascension
(multiplied by cos(delta)) in the sense AGK3 - (AGK2modified), where
the last quantity denotes data from the re-reduced AGK2.
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Modifications:
The machine version of the AGK3 was received on magnetic tape from
the Centre de Donnees Stellaires, Strasbourg in 1978. The version
received had been obtained originally from the Astronomisches
Rechen- Institut in Heidelberg. A preliminary document for a
modified and corrected version of the catalog was produced by Nagy
(1979). The following changes were made to the Heidelberg file in
order to correct some minor errors and to produce a file conforming
more closely to the published version:
1. AGK3 component identifications for stars where more than one
AGK3 star has the same number were changed from upper case
characters (A, B) to lower case (a, b) as in the printed edition.
2. Nine stars in AGK3 zone -00, but in BD zone +00 were found to
have a BD zone of +90. The BD zone for these stars was changed
to +00. These stars are: AGK3 -00 1467, 1510, 1530, 1531, 1532,
1602, 1693, 1774, and 2120.
1-Jul-1997: Explicit decimal points added to floating point fields in
computer-readable version. Document brought up to standard.
[J. Gass, ADC]
1-Sep-1998: filled blanks between sign and value with zeroes in
columns pmRA, pmDE, pmsec, dRA, dDE to allow correct interpretations
[F. Ochsenbien, CDS]
24-Nov-2023: Corrected units for pmRA and pmDE
(arcsec/yr instead of mas/yr)
References:
Cannon, A. J. (1925-1936), The Henry Draper Extension, Ann. Astron. Obs.
Harvard College 100.
Cannon, A. J. and Pickering, E. C. (1918-1924), The Henry Draper Catalogue,
Ann. Astron. Obs. Harvard College 91-99.
Dieckvoss, W. (in collaboration with H. Kox, A. Gunther and E. Brosterhus)
(1975), AGK3 Star Catalogue of Positions and Proper Motions North of
-2.5 Degrees Declination, Hamburg-Bergedorf.
Nagy, T. A. 1979, Documentation for the Machine-Readable Version of the AGK3
Catalogue of Positions and Proper Motions North of -2.5 Degrees
Declination, Systems and Applied Sciences Corporation R-SAW-7/79-35.
Warren, W. H. Jr. and Kress, K. 1980, Astron. Data Center Bull. 1, 19.
Willstrop, R. V. 1983, Bull. Inf. Cent. Donnees Stellaires No. 24, 65.
(End) James E. Gass and Gail L. Schneider [SSDOO/ADC] 01-Jul-1997