{
  "bibcode": "2010GCN.11067....1G",
  "body": "D. Grupe (PSU), W. H. Baumgartner (GSFC/UMBC), J. M. Gelbord (PSU),\nC. Gronwall (PSU), C. Guidorzi (U Ferrara),\nS. T. Holland (CRESST/USRA/GSFC), H. A. Krimm (CRESST/GSFC/USRA) and\nD. M. Palmer (LANL) report on behalf of the Swift Team:\n\nAt 09:13:13 UT, the Swift Burst Alert Telescope (BAT) triggered and\nlocated GRB 100807A (trigger=431128).  Swift slewed immediately to the burst. \nThe BAT on-board calculated location is \nRA, Dec 55.324, +67.679 which is \n   RA(J2000) = 03h 41m 18s\n   Dec(J2000) = +67d 40' 43\"\nwith an uncertainty of 3 arcmin (radius, 90% containment, including \nsystematic uncertainty).  The BAT light curve showed a single-peaked\nstructure with a duration of about 10 sec.  The peak count rate\nwas ~1500 counts/sec (15-350 keV), at ~0 sec after the trigger. \n\nThe XRT began observing the field at 09:14:34.4 UT, 80.8 seconds after\nthe BAT trigger. Using promptly downlinked data we find a bright,\nfading, uncatalogued X-ray source located at RA, Dec 55.30004, 67.67171\nwhich is equivalent to:\n   RA(J2000)  = 03h 41m 12.01s\n   Dec(J2000) = +67d 40' 18.2\"\nwith an uncertainty of 3.9 arcseconds (radius, 90% containment). This\nlocation is 41 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 in excess of the Galactic value (3.31e+21\ncm^-2, Kalberla et al. 2005), with an excess column of 3.8\n(+4.16/-3.25) x 10^21 cm^-2 (90% confidence). \n\nThe initial flux in the 2.5 s image was 9.12e-10 erg cm^-2 s^-1 (0.2-10\nkeV). \n\n\nUVOT took a finding chart exposure of 150 seconds with the White filter\nstarting 90 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. \nThe 8'x8' region for the list of sources generated on-board covers 100% of the\nXRT 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\n0.81. \n\n\n\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": 11067,
  "createdOn": 1281173069000,
  "email": "palmer@lanl.gov",
  "subject": "GRB 100807A: Swift detection of a burst",
  "submitter": "David Palmer at LANL  <palmer@lanl.gov>",
  "eventId": "GRB 100807A"
}