TITLE: GCN GRB OBSERVATION REPORT NUMBER: 4933 SUBJECT: SGR 1900+14: Swift-BAT detection of a bright outburst DATE: 06/03/29 01:54:35 GMT FROM: David Palmer at LANL A. Moretti (INAF-OAB), S. D. Barthelmy (GSFC), D. M. Palmer (LANL), P. Romano (INAF-OAB) and L. Vetere (ASDC) report on behalf of the Swift Team: At 01:28:03 UT 29 March 2006, the Swift Burst Alert Telescope (BAT) triggered and located a bright burst from SGR 1900+14 (trigger=203109). Swift was already pointed at this Soft Gamma-ray Repeater and taking data with the XRT and UVOT. The BAT on-board calculated location is RA,Dec 286.802, +9.329 {19h 07m 12s, +09d 19' 43"} (J2000) with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty), consistent with the known SGR location (1 arcmin). The BAT light curve shows a single intense spike of width 128 ms with 15,000 counts in the brightest 128 ms bin (15-100 keV) with no evidence for emission above 100 keV. This marks the 13th and brightest identified burst from this source in its current episode of activity, and the 6th to occur during pointed observations.