{
  "bibcode": "2012GCN.12810....1I",
  "body": "S. Immler (CRESST/GSFC/UMD), S. D. Barthelmy (GSFC),\nA. P. Beardmore (U Leicester), P. A. Evans (U Leicester),\nN. Gehrels (NASA/GSFC), S. T. Holland (CRESST/USRA/GSFC),\nH. A. Krimm (CRESST/GSFC/USRA), A. Y. Lien (NASA/GSFC/ORAU),\nO. M. Littlejohns (U Leicester), F. E. Marshall (NASA/GSFC),\nC. J. Mountford (U Leicester), P. T. O'Brien (U Leicester),\nK. L. Page (U Leicester), J. L. Racusin (NASA/GSFC),\nC. J. Saxton (UCL-MSSL), B. Sbarufatti (INAF-OAB/PSU),\nM. H. Siegel (PSU), R. L. C. Starling (U Leicester),\nT. N. Ukwatta (MSU) and B.-B. Zhang (PSU) report on behalf of the\nSwift Team:\n\nAt 14:16:24 UT, the Swift Burst Alert Telescope (BAT) triggered and\nlocated GRB 120106A (trigger=511235).  Swift slewed immediately to the burst. \nThe BAT on-board calculated location is \nRA, Dec 66.129, +64.028, which is \n   RA(J2000)  =  04h 24m 31s\n   Dec(J2000) = +64d 01' 42\"\nwith an uncertainty of 3 arcmin (radius, 90% containment, including \nsystematic uncertainty).  The BAT light curve show several overlapping peaks\nstarting ~T-8 sec with a total duration of about 20 sec.  The peak count rate\nwas ~2400 counts/sec (15-350 keV), at ~1 sec after the trigger. \n\nThe XRT began observing the field at 14:17:39.0 UT, 74.9 seconds after\nthe BAT trigger. Using promptly downlinked data we find a bright,\nuncatalogued X-ray source located at RA, Dec 66.11105, 64.03810 which\nis equivalent to:\n   RA(J2000)  = 04h 24m 26.65s\n   Dec(J2000) = +64d 02' 17.2\"\nwith an uncertainty of 3.9 arcseconds (radius, 90% containment). This\nlocation is 46 arcseconds from the BAT onboard position, within the BAT\nerror circle. This position may be improved as more data are received;\nthe latest position is available at http://www.swift.ac.uk/sper.  We\ncannot determine whether the source is fading at the present time. \n\nA power-law fit to a spectrum formed from promptly downlinked event\ndata gives a column density in excess of the Galactic value (2.65 x\n10^21 cm^-2, Kalberla et al. 2005), with an excess column of 4.8\n(+4.97/-3.87) x 10^21 cm^-2 (90% confidence). \n\nThe initial flux in the 2.5 s image was 1.88e-09 erg cm^-2 s^-1 (0.2-10\nkeV). \n\nUVOT took a finding chart exposure of 150 seconds with the White filter\nstarting 84 seconds after the BAT trigger. No credible afterglow candidate has\nbeen found in the initial data products. The 2.7'x2.7' sub-image covers 100% of\nthe XRT error circle. The typical 3-sigma upper limit has been about 19.6 mag. \nData from the list of sources generated on-board are not available at this\ntime. No correction has been made for the expected extinction corresponding to\nE(B-V) of 1.19. \n\nBurst Advocate for this burst is S. Immler (stefan.immler AT nasa.gov). \nPlease contact the BA by email if you require additional information\nregarding Swift followup of this burst. In extremely urgent cases, after\ntrying the Burst Advocate, you can contact the Swift PI by phone (see\nSwift TOO web site for information: http://www.swift.psu.edu/too.html.)",
  "circularId": 12810,
  "createdOn": 1325859973000,
  "email": "scott@milkyway.gsfc.nasa.gov",
  "subject": "GRB 120106A: Swift detection of a burst",
  "submitter": "Scott Barthelmy at NASA/GSFC  <scott@milkyway.gsfc.nasa.gov>",
  "eventId": "GRB 120106A"
}