The EXOSAT Database System

Abstract

The European Space Agency’s X-ray observatory EXOSAT was operational from May 1983 to April 1986 and made 1,780 detailed observations of a wide variety of objects including active galactic nuclei, stellar coronae, cataclysmic variables, white dwarfs, X-ray binaries, clusters of galaxies and supernova remnants. The payload compliment consisted of a large area proportional array, two imaging telescopes (each with a transmission grating spectrometer), and a gas scintillation proportional counter. A unique and highly successful aspect of the mission was the eccentric 90 hour orbit of EXOSAT, which gave for the first time the capability to make uninterrupted observations of the time variability of X-ray sources for several days at a time. The proprietary data rights of an observer were restricted to the first year after data receipt, and by the end of 1987 the entire EXOSAT data archive was open to the astronomical community.