I/243 The PMM USNO-A1.0 Catalogue (Monet 1997) ================================================================================ A Catalog of Astrometric Standards Monet D., Canzian B., Harris H., Reid N., Rhodes A., Sell S. ================================================================================ ADC_Keywords: Surveys ; Photographic catalog ; Photometry, photographic ; Abstract: USNO-A1.0 is a catalog of 488,006,860 sources whose positions can be used for astrometric references. These sources were detected by the Precision Measuring Machine (PMM) built and operated by the U. S. Naval Observatory Flagstaff Station during the scanning and processing of the Palomar Observatory Sky Survey I (POSS-I) O and E plates, the UK Science Research Council SRC-J survey plates, and the European Southern Observatory ESO-R survey plates. The PMM detects and processes at and beyond the nominal limiting magnitude of these surveys, but the large number of spurious detections requires that a filter be used to eliminate as many as possible. USNO-A's sole inclusion requirement was that there be spatially coincident detections (within a 2 arcsecond radius aperture) on the blue and red survey plate. For field centers of -30 degrees and above, data come from POSS-I plates, while data from field centers of -35 and below come from SRC-J and ESO-R plates. File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file out.sam 55 100 *Sample output (out of 526,280,881 stars) read.me 79 260 Author's Original Top-Level Description read.ast 78 144 Discussion of astrometry in USNO-A1.0 read.pht 78 187 Discussion of photometry in USNO-A1.0 read.pmm 79 516 Overview of Precision Measuring Machine usnoa/* . . Compact version of Catalogue (3.4Gbytes) -------------------------------------------------------------------------------- Note on out.sam: this file is actually the result of the execution of the query on the compacted version of USNO-A1.0 at CDS (in subdirectory usnoa, not yet accessible) -------------------------------------------------------------------------------- See also: I/220 : The HST Guide Star Catalog, version 1.1 (Lasker+ 1992) I/252 : The USNO-A2.0 Catalogue (supersedes this version) http://www.usno.navy.mil/pmm/ : The Precision Measuring Machine home page at Flagstaff Station, U.S. Naval Observatory Byte-by-byte Description of file: out.sam -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 13 A13 --- USNO-A1.0 *Original designation in USNO-A1.0 catalogue 15- 24 F10.6 deg RAdeg Right ascension (ICRS) mean of blue/red plates 25- 34 F10.6 deg DEdeg Declination (ICRS) mean of blue/red plates 35 A1 --- GSCflag [G] 'G' when star belongs to GSC (Cat. ) 36 A1 --- Mflag [*] '*' magnitudes are probably wrong 38- 41 F4.1 mag Bmag Magnitude from blue plate 43- 46 F4.1 mag Rmag Magnitude from red plate 48- 55 F8.3 yr Epoch *?=0.0 Mean epoch of position -------------------------------------------------------------------------------- Note on USNO-A1.0: This number allows to retrieve the exact original record: it is made of a zone number (4 digits from 0000 to 1725 representing the distance in 0.1deg to the South Pole, stepped by 75 = 7.5degrees), and a number in the area (8 digits, order by IRCS (J2000) RA); ****Note that this number differs from the USNO-A2.0 one. Note on Epoch: Epoch is the averaged date of observation between the blue and the red plates. -------------------------------------------------------------------------------- History: * 03-Nov-1998: This catalog is superseded (from October 1998) by USNO-A2.0, Cat. Author's Address: Dave Monet US Naval Observatory Flagstaff Station PO Box 1149 (US Mail Only) West Highway 66 (FedEx, UPS, etc.) Flagstaff AZ 86001 USA Voice: 520-779-5132 FAX: 520-774-3626 e-mail: dgm@nofs.navy.mil ================================================================================ (End) Francois Ochsenbein [CDS] 18-Jul-1998