{
  "bibcode": "2008GCN..7598....1S",
  "body": "M. Stamatikos (NASA/ORAU), A. P. Beardmore (U Leicester),\nN. Gehrels (NASA/GSFC), S. D. Hunsberger (PSU),\nC. B. Markwardt (CRESST/GSFC/UMD), J. P. Osborne (U Leicester),\nK. L. Page (U Leicester), D. M. Palmer (LANL),\nT. Sakamoto (NASA/UMBC), R. L. C. Starling (U Leicester) and\nE. Troja (U Leicester/INAF-IASFPA) report on behalf of the Swift\nTeam:\n\nAt 08:51:12 UT, the Swift Burst Alert Telescope (BAT) triggered and\nlocated GRB 080413B (trigger=309111).  Swift started slewing approximately \n70 seconds after the burst. The BAT on-board calculated location is \nRA, Dec 326.134, -19.969 which is \n   RA(J2000) = 21h 44m 32s\n   Dec(J2000) = -19d 58' 08\"\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 3 sec.  The peak count rate\nwas ~15,000 counts/sec (15-350 keV), at ~0.2 sec after the trigger. \n\nThe XRT began observing the field at 08:53:23.8 UT, 131.2 seconds after\nthe BAT trigger. Using promptly downlinked data we find a fading,\nuncatalogued X-ray source with an enhanced position: RA, Dec 326.14434,\n-19.98104 which is equivalent to:\n   RA(J2000)  = 21h 44m 34.64s\n   Dec(J2000) = -19d 58' 51.7\"\nwith an uncertainty of 2.6 arcseconds (radius, 90% containment). This\nlocation is 55 arcseconds from the BAT onboard position, within the BAT\nerror circle. \n\nA power-law fit to a spectrum formed from promptly downlinked event\ndata does not constrain the column density, so we cannot provide limits\non the redshift using spectroscopy and the relation from Grupe et al. \n(2007). A summary of the promptly downlinked data is given at\nhttp://www.swift.ac.uk/sper/309111/. \n\nUVOT took a finding chart exposure of 100 seconds with the White (160-650 nm)\nfilter starting 134 seconds after the BAT trigger. There is a candidate\nafterglow in the rapidly available 2.7'x2.7' sub-image at\n  RA(J2000)  =\t21:44:34.68 = 326.1445\n  DEC(J2000) = -19:58:52.0  = -19.9811\nwith a 1-sigma error radius of about 0.6 arc sec. This position is 0.6 arc\nsec. from the XRT position. The estimated magnitude is 16.5\nwith a 1-sigma error of about 0.5 mag. No correction has been made for the\nexpected extinction corresponding to E(B-V) of 0.04. \n\nBurst Advocate for this burst is M. Stamatikos (michael AT milkyway.gsfc.nasa.gov). \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": 7598,
  "createdOn": 1208078428000,
  "email": "palmer@lanl.gov",
  "subject": "GRB 080413B: Swift detection of a possibly short burst with optical counterpart",
  "submitter": "David Palmer at LANL  <palmer@lanl.gov>",
  "eventId": "GRB 080413B"
}