TITLE: GCN CIRCULAR NUMBER: 21340 SUBJECT: GRB 170714A: Swift detection of a burst DATE: 17/07/14 12:52:55 GMT FROM: David Palmer at LANL A. D'Ai (INAF-IASFPA), D. N. Burrows (PSU), A. Cholden-Brown (PSU), V. D'Elia (ASDC), J. A. Kennea (PSU), H. A. Krimm (NSF/USRA), A. Y. Lien (GSFC/UMBC), F. E. Marshall (NASA/GSFC), K. L. Page (U Leicester), D. M. Palmer (LANL) and B. Sbarufatti (INAF-OAB/PSU) report on behalf of the Swift Team: At 12:25:32 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 170714A (trigger=762535). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 34.321, +1.987 which is RA(J2000) = 02h 17m 17s Dec(J2000) = +01d 59' 14" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). As is usual with an image trigger, the available BAT light curve shows no significant structure. The XRT began observing the field at 12:32:05.3 UT, 392.7 seconds after the BAT trigger. XRT found a bright, uncatalogued X-ray source located at RA, Dec 34.3498, 1.9901 which is equivalent to: RA(J2000) = +02h 17m 23.95s Dec(J2000) = +01d 59' 24.4" with an uncertainty of 5.0 arcseconds (radius, 90% containment). This location is 104 arcseconds from the BAT onboard position, within the BAT error circle. No event data are yet available to determine the column density using X-ray spectroscopy. UVOT took a finding chart exposure of 150 seconds with the U filter starting 869 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 0.03. Burst Advocate for this burst is A. D'Ai (antonino.dai AT ifc.inaf.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.)