/ftp/cats/bincats/USNO_A2



==========================================================================
I/252            The USNO-A2.0 Catalogue                     (Monet+ 1998)
The following files can be converted to FITS (extension .fit .fgz or .fiZ)
	out.sam
==========================================================================
Query from: http://vizier.cds.unistra.fr/viz-bin/VizieR?-source=I/252
==========================================================================

drwxr-xr-x 7 cats archive 177 Dec 22 2013 [Up] drwxr-xr-x 28 cats archive 4096 Sep 14 2010 [TAR file] -rw-r--r-- 1 cats archive 454 Dec 19 2022 .message drwxr-xr-x 2 cats archive 4096 Oct 20 1998 N0000 drwxr-xr-x 2 cats archive 4096 Oct 20 1998 N0730 drwxr-xr-x 2 cats archive 4096 Oct 20 1998 N1500 drwxr-xr-x 2 cats archive 4096 Oct 20 1998 N2230 drwxr-xr-x 2 cats archive 4096 Oct 20 1998 N3000 drwxr-xr-x 2 cats archive 4096 Oct 20 1998 N3730 drwxr-xr-x 2 cats archive 4096 Feb 26 2001 N4500 drwxr-xr-x 2 cats archive 4096 Oct 20 1998 N5230 drwxr-xr-x 2 cats archive 4096 Oct 20 1998 N6000 drwxr-xr-x 2 cats archive 4096 Oct 20 1998 N6730 drwxr-xr-x 2 cats archive 4096 Oct 20 1998 N7500 drwxr-xr-x 2 cats archive 4096 Oct 20 1998 N8230 -r--r--r-- 1 cats archive 4772 Jan 21 2000 ReadMe drwxr-xr-x 2 cats archive 4096 Oct 20 1998 S0000 drwxr-xr-x 2 cats archive 4096 Oct 20 1998 S0730 drwxr-xr-x 2 cats archive 4096 Oct 20 1998 S1500 drwxr-xr-x 2 cats archive 4096 Oct 20 1998 S2230 drwxr-xr-x 2 cats archive 4096 Oct 20 1998 S3000 drwxr-xr-x 2 cats archive 4096 Oct 20 1998 S3730 drwxr-xr-x 2 cats archive 4096 Oct 20 1998 S4500 drwxr-xr-x 2 cats archive 4096 Oct 20 1998 S5230 drwxr-xr-x 2 cats archive 4096 Oct 20 1998 S6000 drwxr-xr-x 2 cats archive 4096 Oct 20 1998 S6730 drwxr-xr-x 2 cats archive 4096 Oct 20 1998 S7500 drwxr-xr-x 2 cats archive 4096 Oct 20 1998 S8230 drwxr-xr-x 2 cats archive 29 Jan 17 2003 bin drwxr-xr-x 2 cats archive 29 Jan 17 2003 bin-solaris drwxr-xr-x 2 cats archive 4096 Jan 12 2023 doc -rw-r--r-- 1 cats archive 6970 Aug 8 2002 readme drwxr-xr-x 2 cats archive 144 Jun 21 2003 src -rw-r--r-- 1 cats archive 25065 Nov 8 2003 src.tar.gz [Uncompressed]
Beginning of ReadMe : I/252 The USNO-A2.0 Catalogue (Monet+ 1998) ================================================================================ USNO-A V2.0, A Catalog of Astrometric Standards Monet D. Bird A., Canzian B., Dahn C., Guetter H., Harris H., Henden A., Levine S., Luginbuhl C., Monet A.K.B., Rhodes A., Riepe B., Sell S., Stone R., Vrba F., Walker R. <U.S. Naval Observatory Flagstaff Station (USNOFS) and Universities Space Research Association (USRA) stationed at USNOFS. (1998)> ================================================================================ ADC_Keywords: Surveys ; Positional data Description: USNO-A2.0 is a catalog of 526,280,881 stars, and is based on a re-reduction of the Precision Measuring Machine (PMM) scans that were the basis for the USNO-A1.0 catalog. The major difference between A2.0 and A1.0 is that A1.0 used the Guide Star Catalog (Lasker et al. 1986, see Cat. I/220) as its reference frame whereas A2.0 uses the ICRF as realized by the USNO ACT catalog (Urban et al. 1997, see Cat. II/246>). A2.0 presents right ascension and declination (J2000, epoch of the mean of the blue and red plate) and the blue and red magnitude for each star. Usage of the ACT catalog as well as usage of new astrometric and photometric reduction algorithms should provide improved astrometry (mostly in the reduction of systematic errors) and improved photometry (because the brightest stars on each plate had B and V magnitudes measured by the Tycho experiment on the Hipparcos satellite). The basic format of the catalog and its compilation is the same as for A1.0, and most users should be able to migrate to this newer version with minimal effort.