
Astronomical Data Center (ADC)
Astrophysics Data Facility, Code 631
NASA/Goddard Space Flight Center
Greenbelt, Maryland 20771, U.S.A.
December 1995
(1) Hughes STX Corporation, Lanham, Maryland, U.S.A.
(2) Centre de Données astronomiques de Strasbourg, France
(3) Astrophysics Data Facility, NASA/GSFC, U.S.A.
Introduction
This is the second volume in a series of CD-ROMs that present a selection of
astronomical catalogs from the
Astronomical Data Center (ADC).
The catalogs
cover a variety of subjects and were selected because they are large or
frequently requested. For example, this CD-ROM contains the large Durchmusterung
catalogs that did not fit on Volume 1, as well as some other large catalogs like
the Hipparcos and Tycho catalogs. There are two versions of this CD-ROM, one
in ASCII (Volume 2, No. 1) and one in FITS (Volume 2, No. 2). The
contents of the ADC CD-ROM, Selected Astronomical Catalogs,
Volume 1 and error report
are available.
The documentation of the catalogs follows the standard adopted by the National Aeronautics and Space Administration (NASA)/ADC and the Centre de Données astronomiques de Strasbourg (CDS) in France. For each catalog a standard documentation file called "readme" was created. By using this readme file as input and software from the CDS (anafile), each catalog was checked for the proper data format, units, allowed data ranges, and correct sorting of the data as specified in the readme. During the verification process errors that were found were corrected in both the data and the documentation. Some catalog data files were reformatted to enable their description in the byte-by-byte tables in the standard readme documentation. This standard format was used with another CDS program (tofits) to convert the data, originally in flat ASCII, to the FITS format. The Flexible Image Transport System (FITS) is the data exchange standard endorsed by the International Astronomical Union (IAU) (See ADC Contact Information). The body of the readme file is incorporated in the FITS primary and table extension headers. A brief summary of the meaning of characters used to specify column charateristics in the Byte-by-byte section of the readme file can be found in a summary of the symbols used .
In Volume 1 a great effort was made to have uniform column labels (FITS keywords) across the whole CD-ROM catalog collection. The documentation standard applied here assures uniformity in the labeling of positional and some other information. However, the column label syntax has been refined to indicate in a uniform way certain relationships between table columns such as "reference to," "uncertainty flag of," "note to," "weights of," "mean error of," etc. In addition, the standard documentation file may define NULL values and specify allowed data ranges and sorting order. The catalog documentation standard, which is in the document directory, requires that SI units be used and thus complies with the IAU recommendations.
Disk Organization and Format
The disk has a simple layout with, at the highest level, separate directories
for the catalogs, software, and additional documentation. The CD-ROM is
formatted according to the ISO 9660 standard, and file the names have been
restricted to eight characters with a three character extension.
The catalog data directory is organized like the ADC on-line FTP archive, with a separate directory for each catalog. The data files are located in the catalogs directory for the ASCII (Volume 2, No. 1) and FITS (Volume 2, No. 2) CD-ROMs. The ADC catalog identification numbers are used as subdirectory names. The software directory contains catalog browsing software for both versions. The additional documentation directory contains a listing of catalogs available from the ADC as of November 1995, a brief overview of the ADC, and some other documents that may be useful.
The format of the data files are either ASCII text files (Volume 2, No. 1) or FITS files (Volume 2, No. 2). The FITS files have an extension .fit, a logical record length of 2,880 bytes and no record terminators. ASCII text files have extensions .dat for data, .doc for documentation, .tex for files in LaTeX or plain TeX, .sty for the LaTeX style file, .f or .for for Fortran code, .txt for text files, .hqx for binhex versions of the Macintosh software files, .bas for QBasic code and .htm for html formatted files. The readme files are text files that have no extension. Each ASCII text file record is terminated by a carriage return (decimal value 13; hex 0D) and a linefeed (decimal value 10; hex 0A). All the catalog data files have been changed to fixed record length by padding short records with blanks. Documentation files have a variable record length.
The software files are in several forms (see below). The FITS Table Browser software (FTB) appears in both compressed form in a .zip file (use PKZIP to decompress) and packaged in a UNIX .tar file. The FITS Table Browser was primarily written to allow owners of an IBM-PC under MS-DOS operating system to access FITS files. Included executables can be identified from their file name extension (.exe). The Macintosh software are HQX files and must be converted. All the other software files are in flat ASCII format.
Catalog Browsing Software
Included in this CD-ROM volume are software tools useful for browsing
and/or extracting data from the catalogs. The same five software packages
are included on both the ASCII version (Volume 2, No. 1) and the FITS version
(Volume 2, No. 2) of the CD-ROM. BBEdit Lite and Browser are for the Macintosh.
FIND, Aurora, and the FITS Table Browser are for IBM PC and compatibles with
the DOS operating system. The FITS Table Browser will also work on some UNIX
systems. They allow the user to edit large files, do catalog specific work,
or access FITS files.
Please note that both freeware and shareware software packages are included on both disks. The user is obliged to comply with the shareware agreement as outlined in the documentation accompanying the software. This applies to the Aurora and Browser shareware. BBEdit Lite is freeware, as explained in the documentation accompanying it. FIND and FTB are freeware and are distributed "as-is" with no guarantee of any kind.
For browsing the FITS files and extracting records of interest, L. Brotzman's FITS Table Browser is useful. It is included in its original form. The FITS Table Browser was primarily written to allow owners of an IBM-PC under the MS-DOS operating system to access FITS files. The Browser software will allow the user to access FITS files on the Macintosh platform. Selected records may be extracted from ASCII tables using the QBasic program FIND provided J.A. Watko. The Aurora and BBEdit Lite editors give access to large files such as those on the CD-ROM. Aurora allows the editing of extremely large files (up to 1GB).
It is hoped that the FITS Table Browser Users' Guide, prepared by T.K. Simmons during his summer student internship at the ADC will help new users of the browser to avoid some of the problems experienced by their predecessors. The FTB Users' Guide describes how to locate and extract the desired records from a FITS table. The original FITS Table Browser was written specifically to work with the catalogs on Volume 1. The features that were designed to take advantage of information given in the Volume 1 FITS header comments do not work with the comments in FITS header files in Volume 2, No. 2. The user is cautioned to review the FITS headers separately and to give particular attention to the specific notes on the fields, which in Volume 2, No. 2 can only be viewed by reading the header comments or the readme file. In all other respects the FITS Table Browser works with the FITS formatted catalog files.
Printed Durchmusterungen
Some printed versions of the Durchmusterungen catalogs are still available from
the ADC. These are identical to the catalogs that appear on the CD-ROM. To
obtain a copy, contact the Coordinated Request and User Support Office of the
NSSDC at Code 633.4 of the NASA/Goddard Space Fight Center, USA. (Internet:
request@nssdca.gsfc.nasa.gov; telephone:
(301)286-6695; fax: (301) 286-1635.)
Acknowledgments
Funding for this work was provided by the NASA Office of Space Science under contract NAS5-30960. The ADC
is overseen and receives guidance from the Astrophysics Data
Facility (ADF) at the NASA/Goddard Space Flight Center.
The National Space Science Data
Center (NSSDC) provided support during the editing and premastering of the
CD-ROM. We acknowledge the assistance provided by Ms. Miranda Robinson, our
technical editor, and the cheerful support of the NSSDC's Richard Chu during the making of the
CD-Recordable premasters. The data were given to the international astronomical data
centers (ADC and CDS) by many authors whose names are listed in the readme
files. Usage of the data in future publications should be acknowledged by
citing the original reference as well as this CD-ROM as the delivery vehicle.
Many people helped to prepare the data in the standard form and validate the
results. We are grateful to Francois Ochsenbein of the Centre de Données
astronomiques de Strasbourg (CDS), France for having implemented the
documentation standard in his catalog preparation software. We thank Lee Brotzman
for his encouragement during the early phases of the project; Nancy Oliversen
for her input during the startup phase; Teheran K. Simmons for his
enthusiastic work on the FITS Table Browser documentation; and Julie Anne Watko
for her work on the FIND program and its documentation. We thank the 113
respondents to an E-mail survey conducted in the fall of 1994 to solicit
community input. The enthusiasm and encouragement that they expressed in
response to the survey kept us motivated.
Cover and disc designs by James Gass and Rob Kilgore. Front cover art, "Tycho at Uraniborg", courtesy Yerkes Observatory. Star photo courtesy Nancy Roman.
References
Selected Astronomical Catalogs, Volume 1. Brotzman, L.E. and Gessner, S.E., 1992,
Astronomical Data Center/NSSDC/IAU, NASA/GSFC, Greenbelt, MD, U.S.A.
ADC Contact Information
The ADC maintains a World Wide Web site at: http://adc.astro.umd.edu/adc.html
and an ftp site ftp://adc.astro.umd.edu/pub/adc/. If errors are found to exist
on the enclosed CD-ROM, they will be documented in the "errors" subdirectory
of the ftp site. Information on the
FITS standard and the NASA FITS Support Office can be found at FITS.
Requesters WITHIN the United States:
NSSDC Coordinated Request and User Support Office
NASA Goddard Space Flight Center
Code 633.4
Greenbelt, Maryland 20771 USA
Requesters OUTSIDE the United States:
World Data Center-A for Rockets and Satellites
NASA Goddard Space Flight Center
Code 633
Greenbelt, Maryland 20771 USA
For all requesters:
Internet: request@nssdca.gsfc.nasa.gov
Telephone: (301) 286-6695; FAX: (301) 286-1635
Astronomical Data Center
Code 631
NASA Goddard Space Flight Center
Greenbelt, Maryland 20771 USA
Gail L. Schneider
Internet: gail.l.schneider@gsfc.nasa.gov or
webmaster@adc.astro.umd.edu
Telephone: (301) 286-8310; FAX: (301) 286-1771
Melissa C. Larkin
Internet: larkin@nssdca.gsfc.nasa.gov
telephone: (301) 286-0679; FAX: (301) 286-1635
N. Paul M. Kuin
Internet: kuin@nssdca.gsfc.nasa.gov
Telephone: (301) 286-0677; FAX: (301) 286-1771
Nancy G. Roman
Internet: nancy.g.roman@gsfc.nasa.gov
Telephone: (301) 286-4070; FAX: (301) 286-1771
Nancy G. Roman
Internet: nancy.g.roman@gsfc.nasa.gov
Telephone: (301) 286-4070; FAX: (301) 286-1771
David T. Leisawitz
Internet: leisawitz@stars.gsfc.nasa.gov
Telephone: (301) 286-0807; FAX: (310) 286-1771
The author index and the keyword index files are a cross reference to the catalogs on the CD-ROM. A complete listing of the catalogs with references and files can be found in the contents.txt file. A listing of the complete ADC catalog holdings and a listing of the complete ADC journal table holdings as of November 1995 as well as the author index and the keyword index to the complete catalog holdings are included in the document directory.