General Catalogue of 33342 stars (Version 1985)
Boss B.
<Carnegie Inst. of Wash. Publ. 468 (1937)>
Description:
The GC is a catalog of standard positions and proper motions for (all) stars brighter than magnitude 7, extending from the north to south celestial poles. Several thousand additional stars promising to yield reasonably accurate proper motions were included in the catalog. The objectives of the work were to provide standard positions and motions of accuracy limited only by the character and abundance of the observational material upon which the data were based and thus to provide a rich supply of data to promote research in many astronomical fields. The machine version of the GC includes both The Henry Draper Catalogue and Durchmusterung identifications for all stars, although the published GC contains only one or the other. The 1985 version corrected many errors present in a previous machine version and included probable errors for the positions and centennial proper motions (not present in the previous version). In this version decimal points have been aligned for all but a very few of the secular variations and third terms. These quantities are given with the same precision as in the printed catalog, and the coded spectral types have been omitted. The following quantities are included in the machine but not the published version: galactic coordinates and DM numbers. The following data are in the published but not the machine version: centennial increments of proper motion in right ascension and declination, probable errors of the right ascension and declination at 1950.0, and remarks. The documentation supplied with the machine catalog gives a byte-by-byte format description, indigenous catalog characteristics, code explanation tables, and changes incorporated to produce this and previous Astronomical Data Center versions.
File Summary:
FileName | Lrecl | Size | Records | Explanations |
ReadMe | 80 | 9KB | This file | |
adc.doc | 76 | 17KB | 536 | Documentation in plain ascii by ADC |
adc.sty | 78 | 2KB | 68 | LaTeX style file for doc.tex |
catalog.dat | 150 | 1889KB | 33342 | The General Catalogue |
doc.tex | 80 | 6KB | 423 | ADC document in LaTeX |
changes.dat | 41 | 11KB | 1186 | Modifications History |
Byte-by-byte Description of file: catalog.dat
Bytes | Format | Units | Label | Explanations |
1-5 | I5 | GC | [1/33342]+ Boss General Catalog (GC) number | |
7-10 | I4 | 0.01mag | Vmag | []?=9999 Visual magnitude, '9999' indicates variability (1) |
12-15 | A4 | SpType | Spectral type | |
16-17 | I2 | h | RAh | Hours RA, equinox 1950.0, epoch 1950.0 |
18-19 | I2 | min | RAm | Minutes RA, equinox 1950.0, epoch 1950.0 |
20-25 | F6.3 | s | RAs | Seconds RA, equinox 1950.0, epoch 1950.0 |
26-29 | F4.1 | a | EpRA | Mean epoch of RA observations (4) |
30-37 | F8.4 | s/a | AvarRA | Annual variation of precession in RA (3) |
38-45 | F8.4 | 0.1ms/a2 | SvarRA | Secular variation in precession in RA (3) |
46-54 | F9.3 | us/a3 | Term3RA | Third term in precession in RA (3) |
55-60 | F6.4 | s/a | pmRA | Proper motion in RA |
61 | A1 | DE- | Sign Dec, equinox 1950.0 | |
62-63 | I2 | deg | DEd | Degrees Dec, equinox 1950.0, epoch 1950.0 |
64-65 | I2 | arcmin | DEm | Minutes Dec, equinox 1950.0, epoch 1950.0 |
66-70 | F5.2 | arcsec | DEs | Seconds Dec, equinox 1950.0, epoch 1950.0 |
71-74 | F4.1 | a | EpDE | Mean epoch of DE observations (4) |
75-81 | F7.3 | arcsec/a | AvarDE | Annual variation of precession in DE (3) |
82-88 | F7.3 | 0.1mas/a2 | SvarDE | Secular variation in precession in DE (3) |
89-95 | F7.2 | uarcsec/a3 | Term3DE | Third term in precession in DE (3) |
96-101 | F6.3 | arcsec/a | pmDE | Proper motion in Dec |
102 | A1 | Remark | [0-9+-] Coded remarks (2) | |
103-115 | A13 | DM | Durchmusterung designation: catalog in bytes 101-102: 'BD', 'CD', 'CP' catalog number in bytes 103-110: SZZNNNNN component identification in bytes 111-112 BD supplement letter in byte 113 | |
116-122 | F7.3 | deg | GLON | Galactic longitude |
123-129 | F7.3 | deg | GLAT | Galactic latitude |
130-135 | I6 | HD | [1/359083]? Henry Draper Catalog (HD) number | |
136 | I1 | m_HD | [0/9]? HD component/multiple code (5) | |
137-140 | F4.3 | arcsec | e_RA | Probable error in RA at epoch |
141-144 | F4.2 | 10mas/a | e_pmRA | Probable error in RA proper motion |
145-148 | F4.3 | arcsec | e_DE | Probable error in DE at epoch |
149-152 | F4.2 | 10mas/a | e_pmDE | Probable error in DE proper motion |
Note (1):
All magnitudes are given to two decimal places in the computer-readable version. Magnitudes underlined in the published version of the catalog are not indicated on the computer-readable version.
Note (2):
Remarks are defined as follows:
0 = No remark given
1 = Spectrum given
2 = Aitken or Innes number given
3 = Aitken or Innes number given with each component having a separate GC number
4 = Other information given
5 = 1+2
6 = 1+3
7 = 1+4
8 = 2+4
9 = 3+4
- = 1+2+4
+ = 1+3+4
Note (3):
The number of decimals can be smaller for positions close to one of the poles (see document)
Note (4):
The first two digits of the year are omitted. Thus 98.8 should be read 1898.8 and 05.3 should be read 1905.3.
Note (5):
The HD component code takes the following values:
0 for single stars or brighter components of doubles with difference in visual magnitude > 0.3mag.
1 designates the brighter component, not necessarily A, for doubles with difference in visual magnitude <= 0.3mag
2 designates the fainter component, not necessarily B, for doubles with difference in visual magnitude <= 0.3mag
9 indicates that two successive HD numbers (HD and HD+1) refer to the same SAO star.
Byte-by-byte Description of file: changes.dat
Bytes | Format | Units | Label | Explanations |
2-6 | I5 | GC | Boss General Catalog (GC) number | |
10-15 | A6 | Field | Field Changed | |
18-25 | A8 | Printed | Old Value | |
29-41 | A13 | New | Current Value |
Historical Notes:
* See section 4 "Remarks and Modifications" in the document file (adc.doc or doc.tex), and the list of modifications in file "changes.dat"
* A previous version is on the "Selected Astronomical Catalogs" Vol. 1 CD-ROM (October 1991), directory /astrom/gc
* This standardized "ReadMe" document file was written in October 1995 at CDS (Francois Ochsenbein), using the ADC documentation written by Nancy G. Roman and Wayne H. Warren Jr.
(End) Francois Ochsenbein [CDS] 13-Oct-1995