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Catalogs Supported by WCSTools |
![[Catalogs]](../catalogs/caticon.gif)
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Catalogs Supported by WCSTools |
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The various WCSTools catalog utility tasks and catalog access subroutines can read many publicly available catalogs of astronomical sources:
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HST Guide Star Catalog,
GSC-ACT Star Catalog,
Tycho 2 Catalog,
USNO A2.0, B1.0, SA2.0, UCAC3, ACT, A1.0, and SA1.0 Catalogs |
CDROM, hard disk copies, World Wide Web |
| GSC II Catalog SDSS Catalog | World Wide Web |
| 2MASS Point Source Catalog | Decompressed copy of DVDROM, World Wide Web |
| SAO, PPM, Hipparcos, Bright Star, IRAS Point Source Catalogs | TDC binary format, World Wide Web |
| Locally created catalogs | TDC ASCII, Starbase tab table, TDC binary |
USNO-A2.0 Catalog | The USNO-A2.0 is a catalog of 526,280,881 stars sorted by right ascension in zone catalogs covering seven and a half degrees of declination each. It 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) reference frame whereas A2.0 uses the ICRF as realized by the USNO ACT catalog (Urban et al. 1997). The catalog is distributed on 11 CDROMs in a very compact format. The quickest way to access it is to put the whole thing on a single hard drive, so the programs in WCSTools can assume a single root directory for the whole catalog rather than one per CDROM. The path to this root directory is specified by the ua2path variable near the start of the file libwcs/uacread.c. This can be overridden at run time by setting the UA2_PATH environment variable. If access is needed to the individual CDROMs, the path to the directory where the 11 CDROMs are mounted is specified by the cdroot variable near the start of that same source file. This can be overridden at run time by setting the UA2_ROOT environment variable. (Added in WCSTools 2.5) |
USNO-B1.0 Catalog |
The USNO-B1.0 is a catalog of 1,042,618,261 objects sorted by right
ascension in zone catalogs of one tenth of a degree of declination each.
The data were obtained from scans of 7,435 Schmidt plates taken
for the various sky surveys during the last 50 years by the
Precision Measuring Machine (PMM) at the US Naval Observatory in Flagstaff,
Arizona. The Tycho-2 Catalog is the astrometric reference. The USNO-B1.0
is believed to provide all-sky coverage, completeness down to V = 21, 0.2
arcsecond astrometric accuracy at J2000, 0.3 magnitude photometric accuracy
in up to five colors, and 85% accuracy for distinguishing stars from
non-stellar objects.
The catalog is distributed by filling a user's disk sent to Flagstaff. The path to the root directory is specified by the ub1path variable near the start of the file libwcs/ubcread.c. This can be overridden at run time by setting the UB1_PATH environment variable. (Added in WCSTools 3.3) |
USNO UCAC3 Catalog |
The UCAC3 is a high density, highly accurate, astrometric catalog of
100,766,420 stars covering the sky completely from -90 to +90 degrees
in declination some areas. Proper motions and photometry are provided for all
stars. Positions are on the ICRS (International Celestial Reference System)
and given for the epoch J2000.0. It is the third release of the ongoing
UCAC project, designed to observe the entire sky from about R magnitude
8 to 16. The observed positional errors are 15-20 mas for stars
in the 10 to 14 magnitude range.
The catalog is distributed on a single double-sided DVD-ROM by the USNO.
WCSTools assumes that the DVD have been copied to a hard disk with the data
residing in a single directory. The path to that directory is specified by
the ucac3path variable near the start of the file libwcs/ucacread.c.
This can be overridden at run time by setting the UCAC3_PATH environment
variable. The obsolete UCAC1 and UCAC2 catalogs are also
supported; substitute 1 or 2 for 3 in the aforementioned parameters.
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GSC II Catalog | The GSC II (currently GSC 2.2) is a catalog of 435,457,355 stars measured from Schmidt plates at the Space Telescope Science Institute. It is magnitude limited to 18.5 in photographic F or 19.5 in photographic J., with bright objects filled in from the Tycho 2 Catalog. Access is over the web to a server at STScI. (Added in WCSTools 2.9.4) |
HST Guide Star Catalog | The GSC is distributed on two CDROMs, one covering the sky north of declination -7:30:00 J2000, and the other covering the sky south of that. If you are only looking at one part of the sky, both disks do not have to be installed at the same time. The Unix paths to the root directories on the CDROMs or to hard disk directories to which they have been copied, are set near the beginning of the file libwcs/gscread.c by the variables cdn and cds. These paths can be overriden by setting the environment variables GSC_NORTH and GSC_SOUTH. To read the GSC from a server over the web, set GSC_PATH. The directory structure from gsc down is built into the program. The sky is divided into 9537 regions, the boundaries of which are kept in a FITS ASCII table file, [root]/tables/regions.tbl on each disk. The regions are grouped into directories which each contain seven and a half degrees of declination. ftp://cfa-ftp.harvard.edu/pub/gsc/CDROM.> |
GSC-ACT Star Catalog |
The GSC-ACT is a recalibration of the HST GSC using the ACT Catalog. It is distributed on two CDROMs by Project Pluto, one covering the sky north of declination -7:30:00 J2000, and the other covering the sky south of that. If you are only looking at one part of the sky, both disks do not have to be installed at the same time. The Unix paths to the root directories on the CDROMs or to hard disk directories to which they have been copied, are set near the beginning of the file libwcs/gscread.c by the variables cdna and cdsa. These paths can be overriden by setting the environment variables GSCACT_NORTH and GSCACT_SOUTH. The directory structure from gsc down is built into the program. To read the GSC-ACT Catalog from a server over the web, set GSCACT_PATH. The sky is divided into 9537 regions, the boundaries of which are kept in a FITS ASCII table file, [root]/tables/regions.tbl on each disk. The regions are grouped into directories which each contain seven and a half degrees of declination. (Added in WCSTools 2.9.4) |
2MASS Point Source Catalog | WCSTools supports both the 470,992,970-source All-Sky release and the 155,569,249-source Interim Data Release 2 (IDR2) of the Two Micron All Sky Survey (2MASS) Point Source Catalog, which was produced by a joint project of the University of Massachusetts and the Infrared Processing and Analysis Center, funded by the National Aeronautics and Space Administration and the National Science Foundation. The entire sky was uniformly scanned in J, H, and K. The All-Sky data was released in May 2003, and needs to be reformatted to be useable. Directions and sofware to do that are available here. The All-Sky catalog is arrange in files containing 0.1-degree bands of declination sorted by right ascension, with one directory per degree of declination. The IDR2 catalog is arranged in files containing right ascension bands which are internally sorted by declination. The path to the directory containing the catalog files is set near the beginning of the file libwcs/tmcread.c by the variables tmcapath, for the All-Sky release, and tmcapath, for IDR2. These paths can be overriden by setting the environment variables TMC_PATH and TMCIDR2_PATH, respectively. The names of the individual catalog files are built into the program. (Added in WCSTools 2.9.4, All-Sky added in WCSTools 3.4.0) |
Sloan Digital Sky Survey Catalog | The Sloan Digital Sky Survey will map one-quarter of the entire sky and perform a redshift survey of galaxies, quasars and stars. Data Release 1 (DR1) covers 2099 square degrees and catalogs 53 million unique objects from CCD images taken through five filters (u-3655A, g-5155A, r-6480A, i-7105A, z-8630A) Photometry is better than 3%, and positions are accurate to about 0.1 arcsecond in each coordinate. (Added in WCSTools 3.5.2) |
USNO-SA2.0 Catalog | The USNO-SA2.0, extracted from the A-2.0 Catalog by David Monet of the US Naval Observatory in Flagstaff, Arizona, contain 50,000,000 sources sorted by right ascension in seven and a half degree zones. The catalog is distributed on a single CDROM in the same format as the A-2.0 Catalog. The path to the root directory on the CDROM or on the hard disk to which the catalog has been copied is specified by the usa2path variable near the start of the file libwcs/uacread.c. This can be overridden at run time by setting the USA2_PATH environment variable. (Added in WCSTools 2.5) |
Tycho-2 Reference Catalog | The Tycho-2 Astrometric and Photometric Reference Catalogue contains positions and proper motions as well as two-colour photometric data for 2,539,913 of the brightest stars in the sky. The Tycho-2 positions and magnitudes are based on precisely the same observations as the Tycho-1 Catalogue collected by the star mapper of the ESA Hipparcos satellite, but Tycho-2 is much bigger and slightly more precise, owing to a more advanced reduction technique. The Unix path to the root directory on the CDROM or to the hard disk directory to which it has been copied, is set near the beginning of the file libwcs/ty2read.c by the variable cdpath. This can be overridden at run time by setting the TY2_PATH environment variable. The directory structure of the CDROM is built into the program, and an index file on the CD is used to determine where to look in the catalog for a specific star or region of the sky. (Added in WCSTools 2.8) |
ACT Reference Catalog | The U.S. Naval Observatory compiled the ACT Reference Catalog, containing 988,758 stars covering the entire sky, to provide accurate proper motions for the majority of the stars in the Tycho Catalogue Positions from new reductions of the Astrographic Catalogue (AC 2000) were combined with those of Tycho, with the large epoch span between the two catalogs yielding proper motions about an order of magnitude more accurate than those published in the Tycho Catalogue. The ACT Reference Catalog include positions, proper motions and error estimates on the Hipparcos System (J2000.0) for epoch J2000.0. Photometric data (B and V) from Tycho are included, as well as cross references to other catalogs. The Unix path to the root directory on the CDROM or to the hard disk directory to which it has been copied, is set near the beginning of the file libwcs/actread.c by the variable cdpath. This can be overridden at run time by setting the ACT_PATH environment variable. The directory structure of the CDROM is built into the program. The sky is divided into 48 regions, each of which covers 30 minutes of right ascension, and, alternatively, 4 regions, each of which covers 45 degrees of declination. This catalog has been superceded by the Tycho 2 Reference Catalog. (Added in WCSTools 2.6) |
Hipparcos Catalog | The Hipparcos astrometric catalog contains positions, proper motions, parallaxes, and B and V magnitudes for 118218 stars. It is one of the final products of ESA's Hipparcos satellite mission. A binary version of this catalog set up for searching by scat is available via anonymous FTP from ftp://cfa-ftp.harvard.edu/pub/gsc/Catalogs/ or online the CfA, in the built-in default directory /data/astrocat2. The path to the directory where the catalog is stored is specified by the bindir variable near the start of the file libwcs/binread.c and defaults to /data/astrocat2. This can be overridden at run time by setting the HIP_PATH or WCS_BINDIR environment variable. |
PPM Catalog | The PPM catalog contains information about 378910 stars, including J2000 positions and proper motions, magnitudes, and, usually, spectral types. The binary version used with this software has been accurately converted to B1950. The PPM catalog is fairly complete to V=9.5, with 102,672 stars fainter than V=10 and 22,395 stars fainter than V=11. An RA-sorted version is used for fast searches, at least away from the poles. Both versions of this catalog is available via anonymous FTP from ftp://cfa-ftp.harvard.edu/pub/gsc/Catalogs/ or online the CfA, in the built-in default directory /data/catalogs. The path to the directory where the catalog is stored is specified by the bindir variable near the start of the file libwcs/binread.c and defaults to /data/catalogs. This can be overridden at run time by setting the PPM_PATH or WCS_BINDIR environment variable. |
SAO Catalog | The SAO catalog contains information about 258,996 stars, including B1950 positions, proper motions, magnitudes, and, often, spectral types. It is more or less complete to V=9, with 4,503 stars fainter than V=10. The unsorted catalog is arranged in 18 10-degree bands of declination, starting with 80-90, sorted by right ascension within each band. An RA-sorted version is used for fast searches, at least away from the poles. Both versions of this catalog is available via anonymous FTP from ftp://cfa-ftp.harvard.edu/pub/gsc/Catalogs/ or online the CfA, in the built-in default directory /data/catalogs. The path to the directory where the catalog is stored is specified by the bindir variable near the start of the file libwcs/binread.c and defaults to /data/catalogs. This can be overridden at run time by setting the SAO_PATH or WCS_BINDIR environment variable. This catalog is available via anonymous FTP from ftp://cfa-ftp.harvard.edu/pub/gsc/Catalogs/ or online the CfA, in the built-in default directory /data/catalogs. (Added in WCSTools 2.5) |
Yale Bright Star Catalogsbsc, imbsc | The Bright Star Catalog contains information about 9,110 stars, including J2000 positions, proper motions, magnitudes, and spectral types. It is more or less complete to V=6.5, and s widely used as a source of basic astronomical and astrophysical data for bright stars. The unsorted catalog is arranged by star number, more or less sorted by B1950 right ascension. An RA-sorted version is used for fast searches, at least away from the poles. Both versions of this catalog are available via HTTP from http://tdc-www.harvard.edu/software/catalogs/bsc5.html. The path to the directory where the catalog is stored is specified by the bindir variable near the start of the file libwcs/binread.c and defaults to /data/catalogs. This can be overridden at run time by setting the BSC_PATH or WCS_BINDIR environment variable. (Added in WCSTools 2.5) |
IRAS Point Source Catalog | The IRAS Point Source Catalog consists of 245,889 sources found and verified by the IRAS (InfraRed Astronomy Satellite). In addition to B1950 positions, flux densities in Janskys (10^-26 W m^-2 Hz^-1) are provided at 12.5, 25, 60, and 100 m^-6 (microns). An L following a flux density indicates that the preceding number is an upper limit; i.e. the source was not detected at that wavelength. Unlike those in the PPM and SAO catalogs, IRAS sources are not uniformly distributed across the sky--IRAS Point Sources tend to be near the galactic equator. This catalog is available via anonymous FTP from ftp://cfa-ftp.harvard.edu/pub/gsc/Catalogs/ or online the CfA, in the built-in default directory /data/catalogs. The path to the directory where the catalog is stored is specified by the bindir variable near the start of the file libwcs/binread.c and defaults to /data/catalogs. This can be overridden at run time by setting the IRAS_PATH or WCS_BINDIR environment variable. (Added in WCSTools 2.5, major update in WCSTools 2.9.4) |
Starbase Tab Table ASCII Catalogs | This file format can be produced by any of the WCSTools files which produce a catalog of positions as output, including (imstar), (imcat), (scat), and their catalog-specific versions. It is also fairly easy to set up such catalogs manually. They consist of an optional header section with each line consisting of a keyword followed by a tab followed by a value. None of these keywords are currently used at input at this time. Then comes a line of tab-separate column headings, followed by a line of -'s under the headings. Currently, WCSTools programs expect to find RA (or ra), DEC (or dec), and MAG (or mag) column headers. The rest of the file consists of single-line entries consisting of tab-separated values. Right ascension (RA) may be given in decimal degrees or as hours:minutes:seconds. Declination (DEC) may be given in decimal degrees or as degrees:minutes:seconds. Currently only J2000 coordinates may be used, but B1950 coordinates will be accepted in the future. Order does not matter. An end-of-file terminates the table. The full path the the directory must be specified. |
TDC ASCII Catalogs | This format was developed so that almost any file with lists of right ascensions and declinations could be used as a catalog with minimum modification. All you have to do is add two lines at the top of the file: the first gives a short name for the catalog and flags which define what information is present, and the second is a more verbose description. If the catalog is not in the current working directory, it is looked for in the directory specified by the catdir variable near the start of the file libwcs/catread.c which defaults to /data/catalogs. catdir can be overridden at run time by setting the WCS_CATDIR environment variable. (Added in WCSTools 2.5) |
TDC Binary Catalogs | This format was developed so that TDC ASCII catalogs could be searched faster. The PPM, SAO,and IRAS Point Source Catalogs are available in this format, and TDC ASCII catalogs can be turned into this format using the catbin program. If the file name ends in ra, it is assumed to be sorted by right ascension, and searches go much faster. If the catalog is not in the current working directory, it is looked for in the directory specified by the bindir variable near the start of the file libwcs/binread.c which defaults to /data/catalogs. bindir can be overridden at run time by setting the WCS_BINDIR environment variable. (Added in WCSTools 2.5) |
USNO-A1.0 Catalog |
The USNO-A1.0, created from plate scans by David Monet of the US Naval
Observatory in Flagstaff, Arizona, contains 488,006,860 sources sorted by right
ascension in seven and a half degree zones. The catalog is distributed on
10 CDROMs in a very compact format. The quickest way to access it is to put
the whole thing on a single hard drive, so the programs in WCSTools can
assume a single root directory for the whole catalog rather than one per
CDROM. The path to this root directory is specified by the ua1path
variable near the start of the file libwcs/uacread.c.
This can be overridden at run time by setting the UA1_PATH environment
variable.
If access is needed to the individual CDROMs, the path to the directory
where the 10 CDROMs are mounted is specified by the cdroot variable
near the start of that same source file. This can be overridden at run time
by setting the UA1_ROOT environment variable.
This catalog is now obsolete; the USNO-A2.0 Catalog should be used instead. |
USNO-SA1.0 Catalog | The USNO-SA1.0, extracted from the A-1.0 Catalog by David Monet of the US Naval Observatory in Flagstaff, Arizona, contain 54,787,624 sources sorted by right ascension in seven and a half degree zones. The catalog is distributed on a single CDROM in the same format as the A-1.0 Catalog. The path to the root directory on the CDROM or on the hard disk to which the catalog has been copied is specified by the usa1path variable near the start of the file libwcs/uacread.c. This can be overridden at run time by setting the USA1_PATH environment This catalog is now obsolete; use the USNO-SA2.0 Catalog instead. |
Tycho Catalog | The 1,058,332-star Tycho Catalogue is one of the primary products of the European Space Agency's astrometric satellite, Hipparcos, which collected data for four years, from November 1989 to March 1993. It measured each of these stars to better than 25 milliarcseconds 130 times over the duration of the mission. In addition to J2000 positions and proper motions, the Tycho Catalogue includes B and V magnitudes which correspond "rather closely to" Johnson B and V. The Center for Astrophysics version of the catalog has had the proper motion added from the epoch of observation, 1991.25, to 2000.0, and a spectral type has been approximated for each star, based on the B-V, to give an idea of the color from a single parameter. It is possible that a subroutine will be written to read the 106-megabyte catalog as it is distributed on the Celestia CDROM, but proper motions for faint stars in the Tycho Catalog have errors larger than their values, so use of the USNO ACT Catalog or Tycho 2 Catalog, which compute proper motions over a longer baseline using the USNO AC2000 Catalog, is preferable. (Added in WCSTools 2.5) |
USNO UCAC2 Catalog |
The UCAC2 is a high density, highly accurate, astrometric catalog of
48,366,996 stars covering the sky completely from -90 to +40 degrees
in declintaion, and going up to +52 degrees in some areas. The
northern limit is a function of right ascension. Proper motions and
photometry are provided for all stars. Positions are on the ICRS
(International Celestial Reference System) and given for the epoch
J2000.0. It is the second release of the ongoing UCAC project, designed
to observe the entire sky from about R magnitude 7.5 to 16. The
observed positional errors are about 20 mas for the stars in the 10
to 14 magnitude range, with about 70 mas at the limiting magnitude
of R about 16.
The catalog is distributed on CDROMs by the USNO. WCSTools assumes that
the cdroms have been copied to a hard disk (or DVD-ROM) with the data residing
in the u2/ subdirectory. The path to the root directory is specified by
the ucac2path variable near the start of the file libwcs/ucacread.c.
This can be overridden at run time by setting the UCAC2_PATH environment
variable. The obsolete UCAC1 catalog is also supported; substitute 1 for 2 in
the aforementioned parameters.
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