1061B I/61B AGK3 Catalogue W Dieckvoss O Heckmann Hamburg-Bergedorf ??? ??? 1975 1975QB6.A15.......D 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) 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. Positional data Proper motions Magnitudes, photographic 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.

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.

AGsign Sign of AGK3 number. --- AGzone AGK3 zone. --- AGnum AGK3 number AGK3 number in increasing order within each declination zone. The field is filled with preceding zeros. --- m_AGnum Component for duplicates Component identification where duplicates AGK3 numbers occur. The lower case letters "a" and "b" may be present. --- Pmag Photographic magnitude from AGK2 mag Sp Spectral type 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. --- RAh Right ascension hours (1950.0) h RAm Right ascension minutes (1950.0) min RAs Right ascension seconds s DE- Sign of declination (1950.0) --- DEd Declination degrees (1950.0) deg DEm Declination minutes arcmin DEs Declination seconds arcsec nobs Number of photographic observations Number of photographic observations used to determine the position. Single-digit numbers are preceded by a zero. --- Ep-1900 Epoch of AGK3 position minus 1900 yr pmRA Annual proper motion in right ascension 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. The suggested format reads the datum in the correct units. mas/yr pmDE Annual proper motion in declination mas/yr dEpoch Epoch difference AGK3-AGK2 yr BD Full BD catalog designation 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 --- m_BD Component of multiple system 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. --- Sum Sum of discrepancy codes 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). --- pmsec Annual proper motion in seconds of RA, computed by dividing by 15cos(delta) s/yr dRA The difference in right ascension in the sense AGK3 - AGK2modified 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. arcsec dDE The difference in declination in the sense AGK3 - AGK2modified arcsec agk3.docDocumentation James E. Gass and Gail L. Schneider SSDOO/ADC 1997Jul01 UNKNOWN UNKNOWN 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] I_61B.xml