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Catalog of Infrared Observations (CIO), Edition 5

Published by High Energy Astrophysics Science Archive Research Center | National Aeronautics and Space Administration | Metadata Last Checked: October 31, 2025 | Last Modified: 2025-09-10
The Fifth Edition of the Catalog of Infrared Observations (CIO) comprises a summary of infrared astronomical observations published in the scientific literature from 1965 through 1997 in the wavelength range 1 micrometer (= 1 micron = 1 um) to 1 millimeter (= 1 mm). This catalog contains infrared observational data for sources outside the Solar System, constructed through a search of the most active scientific journals, IR surveys and catalogs. To date, about 6200 journal articles and 10 major survey catalogs have been included in the database from which this catalog was constructed. The catalog in its original form contains 374,653 individual observations of about 62,000 different infrared sources. More than 8000 of these sources are identifiable with visible objects. For sources with no published IR source position, a nominal position may have been given based on other sources. Nominal positions are usually the best available, but not necessarily the true IR positions. The HEASARC has removed 1136 of the 374,653 entries in the catalog in its original form for which there was no positional information, leaving 373,517 remaining entries in this HEASARC-realized version. The 1136 entries that were removed are listed in the file: <a href="https://heasarc.gsfc.nasa.gov/FTP/heasarc/dbase/misc_files/infrared/deleted_entries.txt">https://heasarc.gsfc.nasa.gov/FTP/heasarc/dbase/misc_files/infrared/deleted_entries.txt</a> In addition to the main catalog, the creators of CIO also generated other files, e.g., bibliographical files, an index file, etc., which are available via the web (in the form of gzipped ASCII files) in the directory: <a href="https://heasarc.gsfc.nasa.gov/FTP/heasarc/dbase/misc_files/infrared/">https://heasarc.gsfc.nasa.gov/FTP/heasarc/dbase/misc_files/infrared/</a>. The bibliographical files (refauth.data.gz refchron.dat.gz, and refs.dat.gz) link observations in the catalog with references to the original articles published in the literature (these references give the standard information plus the full titles). The Index of Infrared Source Positions is contained in the file names.dat.gz and is ordered alphabetically by source name: for sources with no published IR source position, a nominal position (usually the best available, but not necessarily the true IR position) may have been given based on other sources. Nominal position references are indicated in the index. This version of the 5th Edition of the Catalog of Infrared Observations was created by the HEASARC in April 2001 based on ADC/<a href="https://cdsarc.cds.unistra.fr/ftp/cats/II/225">CDS catalog <II/225></a>. Duplicate entries were removed in June 2019. This is a service provided by NASA HEASARC .

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