TITLE: GCN GRB OBSERVATION REPORT NUMBER: 4962 SUBJECT: SGR 1900+14: Swift detection of an outburst DATE: 06/04/14 05:06:39 GMT FROM: Scott Barthelmy at NASA/GSFC A. D. Falcone (PSU), S. D. Barthelmy (GSFC), S. D. Hunsberger (PSU) and D. M. Palmer (LANL) report on behalf of the Swift Team: At 04:35:28 UT 14 Apr 06, the Swift Burst Alert Telescope (BAT) triggered and located an outburst from SGR 1900+14 (trigger=205164). Swift slewed immediately to the burst. The BAT on-board calculated location is RA,Dec 286.799, +9.322 {19h 07m 12s, +09d 19' 19"} (J2000) with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty), 37 arcseconds from the known source location. The BAT light curve shows a single spike with a duration less than 256 msec. The peak count rate was ~3000 counts/sec (15-350 keV), at ~0 sec after the trigger. This is the third burst of comparable size from this source in the past three days. The XRT began taking data at 04:36:17 UT, 49 seconds after the BAT trigger. The XRT on-board centroid algorithm did not find a source in the image and no prompt position is available. However, from the initial light curve, it appears that XRT did detect photons from the outburst. UVOT took a finding chart exposure of 100 seconds with the White (160-650 nm) filter starting 53 seconds after the BAT trigger. No afterglow candidate has been found in the initial data products. The 2.7'x2.7' sub-image covers 25% of the BAT error circle. The typical 3-sigma upper limit has been about 18.5 mag. The 8'x8' region for the list of sources generated on-board covers the known position of SGR1900+14. The list of sources is typically complete to about 18 mag. No correction has been made for the large, but uncertain extinction expected.