{
  "bibcode": "2009GCN..9851....1D",
  "body": "M. De Pasquale (UCL-MSSL), S. D. Barthelmy (GSFC),\nA. P. Beardmore (U Leicester), D. N. Burrows (PSU),\nP. A. Evans (U Leicester), S. T. Holland (CRESST/USRA/GSFC),\nJ. A. Kennea (PSU), H. A. Krimm (CRESST/GSFC/USRA),\nC. B. Markwardt (CRESST/GSFC/UMD), F. E. Marshall (NASA/GSFC),\nC. Pagani (PSU), K. L. Page (U Leicester), D. M. Palmer (LANL),\nP. Romano (INAF-IASFPA), M. Stamatikos (OSU/NASA/GSFC),\nR. L. C. Starling (U Leicester) and T. N. Ukwatta (GSFC/GWU) report\non behalf of the Swift Team:\n\nAt 18:01:14 UT, the Swift Burst Alert Telescope (BAT) triggered and\nlocated possible GRB 090831B (trigger=361477).  Swift slewed immediately \nto the location.  The BAT on-board calculated location is \nRA, Dec 3.619, +27.970 which is \n   RA(J2000)  =  00h 14m 29s\n   Dec(J2000) = +27d 58' 12\"\nwith an uncertainty of 3 arcmin (radius, 90% containment, including \nsystematic uncertainty).  The BAT light curve shows nothing significant\nas is typical for an image trigger. \n\nThe XRT began observing the field at 18:03:44.9 UT, 149.9 seconds after\nthe BAT trigger. No source was detected in the promptly available XRT\ndata. We are waiting for the full dataset to detect and localise the\nXRT counterpart. \n\nUVOT took a finding chart exposure of 150 seconds with the White filter\nstarting 153 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 25% of\nthe BAT error circle. The typical 3-sigma upper limit has been about 19.6 mag. \nThe 8'x8' region for the list of sources generated on-board covers 100% of the\nBAT error circle. The list of sources is typically complete to about 18 mag. No\ncorrection has been made for the expected extinction corresponding to E(B-V) of\n0.03. \n\nDue to the lack of detection by XRT, we cannot confirm\nthat this is a true astrophysical source.  Further analysis\nof the downlinked data (available in ~3 hours) will be required. \n\nBurst Advocate for this burst is M. De Pasquale (mdp 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": 9851,
  "createdOn": 1251743214000,
  "email": "palmer@lanl.gov",
  "subject": "GRB 090831B: Swift detection of a possible burst",
  "submitter": "David Palmer at LANL  <palmer@lanl.gov>",
  "eventId": "GRB 090831B"
}