TITLE: GCN CIRCULAR NUMBER: 14195 SUBJECT: GRB 130211A: Swift detection of a burst DATE: 13/02/11 03:58:20 GMT FROM: Scott Barthelmy at NASA/GSFC S. R. Oates (UCL-MSSL), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), N. Gehrels (NASA/GSFC), J. A. Kennea (PSU), N. P. M. Kuin (UCL-MSSL), C. B. Markwardt (NASA/GSFC), K. L. Page (U Leicester) and B. Sbarufatti (INAF-OAB/PSU) report on behalf of the Swift Team: At 03:36:32 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 130211A (trigger=548276). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 147.523, -42.339 which is RA(J2000) = 09h 50m 05s Dec(J2000) = -42d 20' 18" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows several overlapping peaks with a duration of about 20 sec. The peak count rate was ~900 counts/sec (15-350 keV), at ~1 sec after the trigger. The XRT began observing the field at 03:38:26.0 UT, 113.9 seconds after the BAT trigger. Using promptly downlinked data we find a bright, fading, uncatalogued X-ray source located at RA, Dec 147.53605, -42.34244 which is equivalent to: RA(J2000) = 09h 50m 08.65s Dec(J2000) = -42d 20' 32.8" with an uncertainty of 4.0 arcseconds (radius, 90% containment). This location is 36 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 consistent with the Galactic value of 2.16 x 10^21 cm^-2 (Kalberla et al. 2005). The initial flux in the 2.5 s image was 7.98e-10 erg cm^-2 s^-1 (0.2-10 keV). UVOT took a finding chart exposure of 150 seconds with the White filter starting 125 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. Results from the list of sources generated on-board are not available at this time. No correction has been made for the expected extinction corresponding to E(B-V) of 0.54. Burst Advocate for this burst is S. R. Oates (sro AT mssl.ucl.ac.uk). 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.)