TITLE: GCN CIRCULAR NUMBER: 15656 SUBJECT: GRB 140103A: Swift detection of a burst DATE: 14/01/03 00:55:31 GMT FROM: Scott Barthelmy at NASA/GSFC V. Mangano (PSU), S. D. Barthelmy (GSFC), D. Grupe (PSU), S. T. Holland (STScI), J. A. Kennea (PSU), D. M. Palmer (LANL), T. Sakamoto (AGU), B. Sbarufatti (INAF-OAB/PSU), C. A. Swenson (PSU) and T. N. Ukwatta (MSU) report on behalf of the Swift Team: At 00:30:43 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 140103A (trigger=582773). Swift slewed after 100 sec to the burst. The BAT on-board calculated location is RA, Dec 232.131, +37.749 which is RA(J2000) = 15h 28m 31s Dec(J2000) = +37d 44' 58" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows a single peak with a duration of about 15 sec. The peak count rate was ~1400 counts/sec (15-350 keV), at ~1 sec after the trigger. The XRT began observing the field at 00:33:31.6 UT, 168.3 seconds after the BAT trigger. No source was detected in the 2.5-s promptly available image. We are waiting for the full dataset to detect and localise the XRT counterpart. UVOT took a finding chart exposure of 150 seconds with the White filter starting 171 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 25% of the BAT error circle. The typical 3-sigma upper limit has been about 19.6 mag. The 8'x8' region for the list of sources generated on-board covers 100% of the BAT error circle. The list of sources is typically complete to about 18 mag. No correction has been made for the expected extinction corresponding to E(B-V) of 0.01. Burst Advocate for this burst is V. Mangano (vxm22 AT psu.edu). 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.)