TITLE: GCN CIRCULAR NUMBER: 15728 SUBJECT: GRB 140114A: Swift detection of a burst DATE: 14/01/14 12:23:14 GMT FROM: David Palmer at LANL E. Troja (NASA/GSFC/UMCP), A. P. Beardmore (U Leicester), M. G. Bernardini (INAF-OAB), D. N. Burrows (PSU), V. D'Elia (ASDC), P. A. Evans (U Leicester), D. Malesani (DARK/NBI), F. E. Marshall (NASA/GSFC), A. Maselli (INAF-IASFPA), P. T. O'Brien (U Leicester), K. L. Page (U Leicester), D. M. Palmer (LANL) and M. H. Siegel (PSU) report on behalf of the Swift Team: At 11:57:40 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 140114A (trigger=583861). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 188.482, +27.926 which is RA(J2000) = 12h 33m 56s Dec(J2000) = +27d 55' 35" 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 at least 300 sec. The peak count rate was ~1000 counts/sec (15-350 keV), at ~118 sec after the trigger. The XRT began observing the field at 11:59:46.0 UT, 126 seconds after the BAT trigger. Using promptly downlinked data we find a fading, uncatalogued X-ray source with an enhanced position: RA, Dec 188.5214, 27.9514 which is equivalent to: RA(J2000) = 12h 34m 05.13s Dec(J2000) = +27d 57' 05.1" with an uncertainty of 2.6 arcseconds (radius, 90% containment). This location is 155 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. A power-law fit to a spectrum formed from promptly downlinked event data gives a column density in excess of the Galactic value (1.55 x 10^20 cm^-2, Kalberla et al. 2005), with an excess column of 3.1 (+3.20/-2.63) x 10^21 cm^-2 (90% confidence). UVOT took a finding chart exposure of 150 seconds with the White filter starting 120 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 19.6 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 mag. No correction has been made for the expected extinction corresponding to E(B-V) of 0.02. Burst Advocate for this burst is E. Troja (eleonora.troja AT 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.)