{
  "bibcode": "2008GCN..8169....1G",
  "body": "D. Grupe (PSU), W. H. Baumgartner (GSFC/UMBC), D. N. Burrows (PSU),\nM. M. Chester (PSU), J. R. Cummings (NASA/UMBC),\nS. T. Holland (CRESST/USRA/GSFC), J. A. Kennea (PSU),\nC. B. Markwardt (CRESST/GSFC/UMD), F. E. Marshall (NASA/GSFC),\nD. M. Palmer (LANL), T. N. Ukwatta (GSFC/GWU) and L. Vetere (PSU)\nreport on behalf of the Swift Team:\n\nAt 01:12:23 UT, the Swift Burst Alert Telescope (BAT) triggered and\nlocated GRB 080903 (trigger=323542).  Swift slewed immediately to the burst. \nThe BAT on-board calculated location is \nRA, Dec 86.797, +51.326 which is \n   RA(J2000) = 05h 47m 11s\n   Dec(J2000) = +51d 19' 35\"\nwith an uncertainty of 3 arcmin (radius, 90% containment, including\nsystematic uncertainty).  The BAT light curve showed a broad single-peaked\nstructure with a duration of about 50 sec.  The peak count rate\nwas 1250 counts/sec (15-350 keV), at ~0 sec after the trigger. \n\nThe XRT began observing the field at 01:13:21.8 UT, 58.5 seconds after\nthe BAT trigger. Using promptly downlinked data we find a bright, fading,\nuncatalogued X-ray source located at RA, Dec 86.79071, 51.26363 which\nis equivalent to:\n   RA(J2000)  = 05h 47m 9.77s\n   Dec(J2000) = +51d 15' 49.1\"\nwith an uncertainty of 3.0 arcseconds (radius, 90% containment). This\nlocation is 224 arcseconds from the BAT onboard position, outside the\non-board BAT error circle, but within the BAT ground-calculated error\ncircle. \n\nA power-law fit to a spectrum formed from promptly downlinked event\ndata gives a column density consistent with the Galactic value of\n1.67e+21 cm^-2 (Kalberla et al. 2005). \n\nThe initial flux in the 2.5 s image was 1.80e-09 erg cm^-2 s^-1 (0.2-10\nkeV). \n\nUVOT took a finding chart exposure of 400 seconds with the V filter\nstarting 75  seconds after the BAT trigger. No afterglow candidate\nhas been found in the  initial data products. The 2.7'x2.7' sub-image\ncovers 100% of the XRT error  circle. The 3-sigma upper limit at the\nlocation of the XRT candidate is 19.4 mag. No correction has  been\nmade for the expected extinction of about 0.7 magnitudes. \n\nBurst Advocate for this burst is D. Grupe (grupe AT astro.psu.edu). \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": 8169,
  "createdOn": 1220405911000,
  "email": "dxb15@psu.edu",
  "subject": "GRB 080903: Swift detection of a burst",
  "submitter": "David Burrows at PSU/Swift  <dxb15@psu.edu>",
  "eventId": "GRB 080903"
}