TITLE: GCN CIRCULAR NUMBER: 16000 SUBJECT: GRB 140320A: Swift detection of a burst DATE: 14/03/20 02:42:04 GMT FROM: David Palmer at LANL J. K. Cannizzo (NASA/UMBC), J. A. Kennea (PSU), A. Y. Lien (NASA/GSFC/ORAU), C. J. Mountford (U Leicester), D. M. Palmer (LANL) and B. Sbarufatti (INAF-OAB/PSU) report on behalf of the Swift Team: At 02:12:45 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 140320A (trigger=592544). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 281.857, -11.173 which is RA(J2000) = 18h 47m 26s Dec(J2000) = -11d 10' 21" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a double-peaked structure with two peaks separated by ~140 sec and a total duration of about 150 sec. The peak count rate was ~3700 counts/sec (15-350 keV), at ~0 sec after the trigger. No source was detected in 57 s of promptly downlinked data. We are waiting for the full dataset to detect and localise the XRT counterpart. Due to partial real-time telemetry, no further information is available at this time. However the burst was also detected by the Fermi-GBM instrument, verifying its reality. More details will be available following the next ground pass telemetry dump. Burst Advocate for this burst is J. K. Cannizzo (cannizzo AT milkyway.gsfc.nasa.gov). Please contact the BA by email if you require additional information regarding Swift followup of this burst. In extremely urgent cases, after trying the Burst Advocate, you can contact the Swift PI by phone (see Swift TOO web site for information: http://www.swift.psu.edu/too.html.)