A search for X-ray bursts from extragalactic supernovae using the HEAO 1 satellite

The soft X-ray data from the low energy detectors of the HEAO 1 A-2 experiment are surveyed in the 0.15-3.0 keV range to search for X-ray bursts (less than 1 hour) from extragalactic supernovae predicted by Klein and Chevalier. To within the operating sensitivity of 0.08 photons per sq cm/s no events were discovered from the first 8 months of operation. This is consistent with the theoretical prediction that the probability of finding one such event is small. The HEAO 2 satellite should be capable of detecting supernovae out to 2000 Mpc; these events are of cosmological interest.