TITLE: GCN CIRCULAR NUMBER: 13475 SUBJECT: Trigger 526660: Swift detection of 1 E 1841-045 (aka Kes 73) DATE: 12/07/15 04:56:24 GMT FROM: Scott Barthelmy at NASA/GSFC S. D. Barthelmy (GSFC), N. Gehrels (NASA/GSFC), S. R. Oates (UCL-MSSL) and T. Sakamoto (NASA/UMBC) report on behalf of the Swift Team: At 04:31:08 UT, the Swift Burst Alert Telescope (BAT) triggered on an outburst 1E 1841-045 (aka Kes 73) (trigger=526660). Swift did not slew because it was given a low merit value (as is typical for known-source triggers). The BAT on-board calculated location is RA, Dec 280.349, -4.958, which is RA(J2000) = 18h 41m 24s Dec(J2000) = -04d 57' 27" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows a single spike with a duration less than 64 msec. The peak count rate was ~1800 counts/sec (15-350 keV), at ~0 sec after the trigger. We note that BAT previously triggered on this source on 02 July 2011. There is a known SGR at this location.