This catalog gives information for each Einstein Observatory Imaging Proportional Counter (IPC) observation used in the Einstein Observatory Source Catalog (EOSCAT). It also contains information relating to individual "HUTS" (HEAO Universal Time), time segments of data which were summed to create IPC Sequence numbers. Each HUT is designated by its initial major frame
The Einstein Observatory is the second of NASA's three High Energy Astrophysical Observatories, HEAO-2, renamed Einstein after launch, and was the first fully imaging X-ray telescope put into space. It observed in the energy range 0.2-20keV. It was launched on 12 November 1978, and remained in operation until April 1981. The High Resolution Imager (HRI) is one fo the four instruments aboard the Einstein Observatory, operating in the 0.2-3.0keV energy range, with a spatial resolution of a few arcseconds, and a field of view of 25arcmin. Field and source parameters observed with this instrument are given here.