TITLE: GCN CIRCULAR NUMBER: 23344 SUBJECT: Trigger 867343: Swift detection of SGR1806-20 DATE: 18/10/16 15:54:43 GMT FROM: Scott Barthelmy at NASA/GSFC S. D. Barthelmy (GSFC), A. D'Ai (INAF-IASFPA), V. D'Elia (SSDC), J. A. Kennea (PSU), B. Sbarufatti (PSU) and A. Tohuvavohu (PSU) report on behalf of the Neil Gehrels Swift Observatory Team: At 15:40:15 UT, the Swift Burst Alert Telescope (BAT) triggered and located SGR1806-20 (trigger=867343). Swift did not slew to the source because of an observing constraint. The BAT on-board calculated location is RA, Dec 272.130, -20.376, which is RA(J2000) = 18h 08m 31s Dec(J2000) = -20d 22' 32" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows two peaks with a duration of about 2 sec. The peak count rate was ~3000 counts/sec (15-350 keV), at ~0 sec after the trigger. Due to a Moon observing constraint, Swift cannot slew to the BAT position until 2018 October 16 at 21:16 UT. A Swift XRT/UVOT observation is planned for October 17th starting a 01:07 UT.