{
  "bibcode": "2009GCN..8932....1B",
  "body": "A. P. Beardmore (U Leicester), J. R. Cummings (NASA/UMBC),\nS. T. Holland (CRESST/USRA/GSFC), C. B. Markwardt (CRESST/GSFC/UMD),\nC. Pagani (PSU), K. L. Page (U Leicester) and D. M. Palmer (LANL)\nreport on behalf of the Swift Team:\n\nAt 05:19:51 UT, the Swift Burst Alert Telescope (BAT) triggered and\nlocated GRB 090305 (trigger=345127).  Swift slewed immediately to the burst. \nThe BAT on-board calculated location is RA, Dec 241.756, -31.567 which is \n   RA(J2000) = 16h 07m 02s\n   Dec(J2000) = -31d 34' 00\"\nwith an uncertainty of 3 arcmin (radius, 90% containment, including \nsystematic uncertainty).  The BAT light curve showed a single short spike\nwith a duration of about 0.4 sec.  The peak count rate\nwas ~2500 counts/sec (15-350 keV), at ~0 sec after the trigger. \n\nThe XRT began observing the field at 05:21:23.8 UT, 92.7 seconds after\nthe BAT trigger. No source was detected in the promptly available XRT\ndata in an exposure time of 92.8 seconds before Swift slewed away. We are \nwaiting for the full dataset to detect and localise the\nXRT counterpart. \n\n\nUVOT took a finding chart exposure of 102 seconds with the White filter\nstarting 96 seconds after the BAT trigger. No credible afterglow candidate has\nbeen found in the initial data products. Because part of the 2.7'x2.7'\nsub-image was not received, the overlap with the BAT error circle is uncertain. \nThe overlap is at most 25%. The coverage of the BAT error circle by the 8'x8'\nregion for the list of sources generated on-board is uncertain because the\nlarge number of sources filled the available telemetry. No correction has been\nmade for the expected extinction corresponding to E(B-V) of 0.22. \n\n\n\n\nWe note the presence of a ROSAT survey source, 1RXS J160703.2-313251,\nwithin the BAT error circle.  Further data are required to determine\nwhether this object is related to the burst. \n\nBurst Advocate for this burst is A. P. Beardmore (apb AT star.le.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": 8932,
  "createdOn": 1236231522000,
  "email": "palmer@lanl.gov",
  "subject": "GRB 090305: Swift detection of a short burst",
  "submitter": "David Palmer at LANL  <palmer@lanl.gov>",
  "eventId": "GRB 090305"
}