The new IPN has been self-calibrated with the quite fortuitous occurrence of the giant SGR flare of 1998 August 27, given its precisely known SGR1900 +14 source location (see IAU Circulars 7002, 7004 and 7005). The Ulysses detector response was not saturated ([Hurley et al. 1999]), but this 1979-March-5-like event was of sufficient intensity to saturate the larger detectors on GGS-Wind Konus and NEAR. However, the times of a modest precursor and of the onset of the largest increase were free of distortion. The resulting analysis gave a source of several arc minutes precisely agreeing with the SGR location. Thus, the IPN detection of future events from known SGRs or of future GRBs localized by BeppoSAX will demonstrate its continued timing stability and calibration.
Copyright The European Southern Observatory (ESO)