TITLE: GCN CIRCULAR NUMBER: 18893 SUBJECT: GRB 160119A: Swift detection of a burst DATE: 16/01/19 03:18:51 GMT FROM: David Palmer at LANL F. E. Marshall (NASA/GSFC), D. N. Burrows (PSU), J. A. Kennea (PSU), H. A. Krimm (CRESST/GSFC/USRA), K. L. Page (U Leicester) and D. M. Palmer (LANL) report on behalf of the Swift Team: At 03:06:08 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 160119A (trigger=671014). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 211.893, +20.474 which is RA(J2000) = 14h 07m 34s Dec(J2000) = +20d 28' 28" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows low level variability followed by a peak from T+120 to T+180. The peak count rate was ~3000 counts/sec (15-350 keV), at ~142 sec after the trigger. The XRT began observing the field at 03:08:48.0 UT, 159.8 seconds after the BAT trigger. Using promptly downlinked data we find a bright, fading, uncatalogued X-ray source located at RA, Dec 211.92111, 20.46161 which is equivalent to: RA(J2000) = 14h 07m 41.07s Dec(J2000) = +20d 27' 41.8" with an uncertainty of 3.8 arcseconds (radius, 90% containment). This location is 104 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 (3.08 x 10^20 cm^-2, Willingale et al. 2013), with an excess column of 3.4 (+2.60/-1.22) x 10^21 cm^-2 (90% confidence). The initial flux in the 0.1 s image was 2.75e-08 erg cm^-2 s^-1 (0.2-10 keV). UVOT took a finding chart exposure of 150 seconds with the White filter starting 168 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 0.03. Burst Advocate for this burst is F. E. Marshall (marshall AT milkyway.gsfc.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.)