{
  "bibcode": "2013GCN.14345....1K",
  "body": "H. A. Krimm (CRESST/GSFC/USRA), S. D. Barthelmy (GSFC),\nW. H. Baumgartner (GSFC/UMBC), J. A. Kennea (PSU),\nN. P. M. Kuin (UCL-MSSL), V. Mangano (INAF-IASFPA),\nA. Maselli (INAF-IASFPA), D. M. Palmer (LANL),\nJ. L. Racusin (NASA/GSFC), M. H. Siegel (PSU),\nE. Troja (NASA/GSFC/UMCP) and T. N. Ukwatta (MSU) report on behalf of\nthe Swift Team:\n\nAt 02:13:57 UT, the Swift Burst Alert Telescope (BAT) triggered and\nlocated a possible GRB (trigger=552142).  Swift slewed immediately to the burst. \nThe BAT on-board calculated location is \nRA, Dec 270.747, +21.327, which is \n   RA(J2000)  =  18h 02m 59s\n   Dec(J2000) = +21d 19' 38\"\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 02:16:10.7 UT, 133.1 seconds after\nthe BAT trigger. No source was detected in 1.5 ks of promptly\ndownlinked data. We are waiting for the full dataset to detect and\nlocalise the XRT counterpart. \n\nUVOT took a finding chart exposure of 150 seconds with the White filter\nstarting 136 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\n0.11. \n\nGround reprocessing of the immediately available BAT data found\na decreased significance at the on-board detection location. \nThis, along with the non-detection of a source in the XRT and\nUVOT data means that we cannot confirm that this is a\ntrue astrophysical event.  A final determination of the\nreality of this source will require analysis of the full \nground-linked data set. \n\nBurst Advocate for this burst is H. A. Krimm (krimm 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": 14345,
  "createdOn": 1364438954000,
  "email": "scott@milkyway.gsfc.nasa.gov",
  "subject": "Swift Trigger 552142: a possible GRB",
  "submitter": "Scott Barthelmy at NASA/GSFC  <scott@milkyway.gsfc.nasa.gov>"
}