TITLE: GCN CIRCULAR NUMBER: 15784 SUBJECT: GRB 140206A: Swift detection of a burst DATE: 14/02/06 07:49:38 GMT FROM: Scott Barthelmy at NASA/GSFC A. Y. Lien (NASA/GSFC/ORAU), S. D. Barthelmy (GSFC), M. M. Chester (PSU), V. D'Elia (ASDC), D. Malesani (DARK/NBI), A. Maselli (INAF-IASFPA), K. L. Page (U Leicester), D. M. Palmer (LANL) and M. H. Siegel (PSU) report on behalf of the Swift Team: At 07:17:20 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 140206A (trigger=585834). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 145.350, +66.750 which is RA(J2000) = 09h 41m 24s Dec(J2000) = +66d 45' 01" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows a multi-peaked structure with a duration of about 80 sec. The peak count rate was ~19000 counts/sec (15-350 keV), at ~60 sec after the trigger. The XRT began observing the field at 07:18:04.0 UT, 43.9 seconds after the BAT trigger. Using promptly downlinked data we find a bright, uncatalogued X-ray source located at RA, Dec 145.33438, 66.76074 which is equivalent to: RA(J2000) = 09h 41m 20.25s Dec(J2000) = +66d 45' 38.7" with an uncertainty of 3.7 arcseconds (radius, 90% containment). This location is 44 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. We cannot determine whether the source is fading at the present time. A power-law fit to a spectrum formed from promptly downlinked event data gives a column density consistent with the Galactic value of 4.79 x 10^20 cm^-2 (Kalberla et al. 2005). The initial flux in the 2.5 s image was 9.62e-09 erg cm^-2 s^-1 (0.2-10 keV). UVOT results are not available at this time. Burst Advocate for this burst is A. Y. Lien (yarleen AT gmail.com). 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.)