TITLE: GCN CIRCULAR NUMBER: 13237 SUBJECT: Trigger 519868: Swift detection of SGR1806-20 DATE: 12/04/10 23:23:06 GMT FROM: Scott Barthelmy at NASA/GSFC S. D. Barthelmy (GSFC), P. D'Avanzo (INAF-OAB), N. Gehrels (NASA/GSFC), E. A. Hoversten (PSU), C. B. Markwardt (NASA/GSFC) and B. Sbarufatti (INAF-OAB/PSU) report on behalf of the Swift Team: At 23:08:33 UT, the Swift Burst Alert Telescope (BAT) triggered and located an outburst from SGR1806-20 (trigger=519868). Swift did not slew because of the Moon observering constraint. The BAT on-board calculated location is RA, Dec 272.153, -20.410 which is RA(J2000) = 18h 08m 37s Dec(J2000) = -20d 24' 35" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows a single spike with a duration of about 0.2 sec. The peak count rate was ~13,000 counts/sec (15-350 keV), at ~0 sec after the trigger. Due to an observing constraint Swift will be unable to observe this field with the XRT and UVOT instruments until 12 April at 14:00 UT.