{
  "bibcode": "2009GCN.10148....1O",
  "body": "S. R. Oates (UCL-MSSL), S. D. Barthelmy (GSFC),\nW. H. Baumgartner (GSFC/UMBC), A. P. Beardmore (U Leicester),\nP. A. Evans (U Leicester), N. Gehrels (NASA/GSFC),\nS. T. Holland (CRESST/USRA/GSFC), J. A. Kennea (PSU),\nH. A. Krimm (CRESST/GSFC/USRA), C. B. Markwardt (CRESST/GSFC/UMD),\nF. E. Marshall (NASA/GSFC), P. T. O'Brien (U Leicester),\nK. L. Page (U Leicester), D. M. Palmer (LANL),\nA. Rowlinson (U Leicester), T. Sakamoto (NASA/UMBC),\nM. H. Siegel (PSU), M. Stamatikos (OSU/NASA/GSFC), M. A. Stark (PSU),\nT. N. Ukwatta (GSFC/GWU) and L. Vetere (PSU) report on behalf of the\nSwift Team:\n\nAt 21:49:03 UT, the Swift Burst Alert Telescope (BAT) triggered and\nlocated GRB 091109B (trigger=375409).  Swift slewed immediately to the burst. \nThe BAT on-board calculated location is \nRA, Dec 112.717, -54.080 which is \n   RA(J2000)  =  07h 30m 52s\n   Dec(J2000) = -54d 04' 48\"\nwith an uncertainty of 3 arcmin (radius, 90% containment, including \nsystematic uncertainty).  The BAT light curve shows a single spike\nwith a duration of about 0.4 sec.  The peak count rate\nwas ~30,000 counts/sec (15-350 keV), at ~0 sec after the trigger. \n\nThe XRT began observing the field at 21:50:21.1 UT, 78.1 seconds after\nthe BAT trigger. Using promptly downlinked data we find an uncatalogued\nX-ray source with an enhanced position: RA, Dec 112.7349, -54.0896\nwhich is equivalent to:\n   RA(J2000)  = 07h 30m 56.39s\n   Dec(J2000) = -54d 05' 22.7\"\nwith an uncertainty of 3.6 arcseconds (radius, 90% containment). This\nlocation is 51 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. \n\nA power-law fit to a spectrum formed from promptly downlinked event\ndata gives a column density consistent with the Galactic value of\n9.23e+20 cm^-2 (Kalberla et al. 2005). \n\nUVOT took a finding chart exposure of 250 seconds with the U filter starting\n296 seconds after the BAT trigger. No credible afterglow candidate has been\nfound in the initial data products. The 2.7'x2.7' sub-image covers 100% of the\nXRT error circle. The 3-sigma upper limit is 20.3 mag. The\ncoverage of the XRT error circle by the 8'x8' region for the list of sources\ngenerated on-board is uncertain because the large number of sources filled the\navailable telemetry. No correction has been made for the expected extinction\ncorresponding to E(B-V) of 0.17. \n\nBurst Advocate for this burst is S. R. Oates (sro AT mssl.ucl.ac.uk). \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": 10148,
  "createdOn": 1257804618000,
  "email": "scott@lheamail.gsfc.nasa.gov",
  "subject": "GRB 091109B: Swift detection of a short burst",
  "submitter": "Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>",
  "eventId": "GRB 091109B"
}