TITLE: GCN CIRCULAR NUMBER: 16097 SUBJECT: GRB 140412A: Swift detection of a burst DATE: 14/04/12 22:33:10 GMT FROM: David Burrows at PSU/Swift V. D'Elia (ASDC), D. N. Burrows (PSU), S. T. Holland (STScI), L. Izzo (URoma/ICRA), F. E. Marshall (NASA/GSFC), T. Sakamoto (AGU) and B. Sbarufatti (INAF-OAB/PSU) report on behalf of the Swift Team: At 22:20:49 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 140412A (trigger=595608). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 145.050, -65.809 which is RA(J2000) = 09h 40m 12s Dec(J2000) = -65d 48' 31" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a FRED-like structure with a duration of about 20 sec. The peak count rate was ~2000 counts/sec (15-350 keV), at ~0 sec after the trigger. The XRT began observing the field at 22:24:17.0 UT, 207.2 seconds after the BAT trigger. Using promptly downlinked data we find an uncatalogued X-ray source with an enhanced position: RA, Dec 144.9713, -65.8226 which is equivalent to: RA(J2000) = 09h 39m 53.11s Dec(J2000) = -65d 49' 21.3" with an uncertainty of 3.2 arcseconds (radius, 90% containment). This location is 125 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 150 seconds with the White filter starting 236 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 none of the XRT error circle. 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 0.22. 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.)