TITLE: GCN CIRCULAR NUMBER: 19182 SUBJECT: GRB 160314A: Swift detection of a burst DATE: 16/03/14 11:46:45 GMT FROM: Kim Page at U.of Leicester V. D'Elia (ASDC), A. A. Breeveld (UCL-MSSL), P.A. Evans (U Leicester), L. Izzo (URoma1), J. A. Kennea (PSU), A. Y. Lien (GSFC/UMBC), F. E. Marshall (NASA/GSFC), K. L. Page (U Leicester) and B. Sbarufatti (INAF-OAB/PSU) report on behalf of the Swift Team: At 11:32:51 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 160314A (trigger=679120). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 112.781, +17.001 which is RA(J2000) = 07h 31m 07s Dec(J2000) = +17d 00' 03" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a multi-peaked structure with a duration of about 20 sec. The peak count rate was ~1700 counts/sec (15-350 keV), at ~1 sec after the trigger. The XRT began observing the field at 11:34:22.7 UT, 91.0 seconds after the BAT trigger. Using promptly downlinked data we find an uncatalogued X-ray source with an enhanced position: RA, Dec 112.7891, 16.9987 which is equivalent to: RA(J2000) = 07h 31m 09.39s Dec(J2000) = +16d 59' 55.5" with an uncertainty of 2.1 arcseconds (radius, 90% containment). This location is 29 arcseconds from the BAT onboard position, within the BAT error circle. This position may be improved as more data are received; the latest position is available at http://www.swift.ac.uk/sper. No spectrum from the promptly downlinked event data is yet available to determine the column density. UVOT took a finding chart exposure of 250 seconds with the U filter starting 151 seconds after the BAT trigger. No credible afterglow candidate has been found in the initial data products. The 2.7'x2.7' sub-image covers 100% of the XRT error circle. The typical 3-sigma upper limit has been about 19.2 mag. The 8'x8' region for the list of sources generated on-board covers 100% of the XRT error circle. The list of sources is typically complete to about 18.0 mag. No correction has been made for the expected extinction corresponding to E(B-V) of 0.08. Burst Advocate for this burst is V. D'Elia (delia AT asdc.asi.it). 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.)