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HESSCAT - HESS (High Energy Stereoscopic System) Source Catalog



H.E.S.S. is a system of Imaging Atmospheric Cherenkov Telescopes for the investigation of cosmic gamma rays in the 100 GeV energy range. The name H.E.S.S. stands for High Energy Stereoscopic System, and should also remind us of Victor Hess, who received in 1936 the Nobel Prize in Physics for his discovery of cosmic radiation. The instrument allows us to explore gamma-ray sources with intensities at a level of a few thousandth parts of the flux of the Crab nebula. H.E.S.S. is located in Namibia, near the Gamsberg, an area well known for its excellent optical quality. The first of the four telescopes of Phase I of the H.E.S.S. project went into operation in Summer 2002; all four were operational in December 2003, and were officially inaugurated on September 28, 2004. In recognition of its scientific results, H.E.S.S. was awarded the 2006 Descartes Prize for Research of the European Commission.


The HESSCAT database table was last updated on 19 March 2023.


The file


This database table, first created in April 2008, contains the H.E.S.S. source list created by Dr. W. Hofmann and is based on the HTML table at The latter table is updated regularly and this HEASARC table will be updated within one week of any updates.


The designation of the H.E.S.S. source using the 'HESS' prefix and a J2000.0 coordinate string, as recommended by the CDS Dictionary of Nomenclature of Celestial Objects.

The Right Ascension of the gamma-ray source in the selected equinox. This was given in J2000.0 coordinates to a precision of 1 second of time in the original table.

The Declination of the gamma-ray source in the selected equinox. This was given in J2000.0 coordinates to a precision of 1 arcsecond in the original table.

The Galactic Longitude of the gamma-ray source.

The Galactic Latitude of the gamma-ray source.

The maximum flux of the gamma-ray source, in Crab units.

The angular radius of the gamma-ray source, in arcminutes.

The counterpart of the gamma-ray source and/or other source designations.

Publication reference(s) for the H.E.S.S. source.

The link to the H.E.S.S. Source of the Month page, if one exists for the particular source.

Contact Person

Questions regarding the HESSCAT database table can be addressed to the HEASARC User Hotline.
Page Author: Browse Software Development Team
Last Modified: Friday, 20-Mar-2015 17:50:01 EDT