TITLE: GCN CIRCULAR NUMBER: 8835 SUBJECT: AXP 1E1547.0-5408: Fermi GBM observations DATE: 09/01/22 08:39:21 GMT FROM: Valerie Connaughton at MSFC Valerie Connaughton (UAH) and Michael Briggs (UAH) report on behalf of the Fermi GBM Team: "At 00:53:52.17 UT on 22 Jan 2009, the Fermi Gamma-Ray Burst Monitor triggered on AXP 1E1547.0-5408 (trigger 254278434 / 090122037). Since then, GBM has seen 18 triggers from this source including one trigger also detected by the Swift-BAT (Palmer et al. 2009, GCN 8833). The trigger rate is consistent with constant source activity in the form of short and often very bright pulses occurring within an interval of a few seconds to about 150s between pulses. We estimate the source activity is constant because the time between triggers is between 600s and 740s outside of SAA passages and periods during which the source is occulted by the Earth. The minimum possible trigger spacing for GBM is 596 seconds. Because of the high data rate these triggers have caused, it is not yet possible to perform spectral analysis of any of these events. We estimate from our real-time data, however, that the source is visible at least up to 100 keV and is not visible above 300 keV."