{
  "bibcode": "2013GCN.15384....1C",
  "body": "S. B. Cenko (GSFC), S. T. Holland (STScI), L. Izzo (URoma/ICRA),\nK. L. Page (U Leicester), D. M. Palmer (LANL),\nB. Sbarufatti (INAF-OAB/PSU) and M. H. Siegel (PSU) report on behalf\nof the Swift Team:\n\nAt 06:39:32 UT, the Swift Burst Alert Telescope (BAT) and located \na possible GRB in an image trigger (trigger=575905).  Swift slewed \nimmediately to the location. \nThe BAT on-board calculated location is \nRA, Dec 15.547, +32.487 which is \n   RA(J2000) = 01h 02m 11s\n   Dec(J2000) = +32d 29' 13\"\nwith an uncertainty of 3 arcmin (radius, 90% containment, including \nsystematic uncertainty).  As is usual for an image trigger, there\nis no obvious variation in the BAT lightcurve. \n\nThe XRT began observing the field at 06:41:33.9 UT, 121.1 seconds after\nthe BAT trigger. No source was detected in the 2.5-s promptly available\nimage. We are waiting for the full dataset to detect and localise the\nXRT counterpart. \n\nUVOT took a finding chart exposure of 150 seconds with the White filter\nstarting 127 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\n0.07. \n\nBecause the BAT image peak is of marginal significance (7.06 sigma)\nand because there is only 2.5 seconds of XRT data immediately\navailable, which does not show a counterpart, we cannot yet confirm\nor deny the reality of this possible GRB.  A final determination\nof the nature of this trigger will require the full set of\ndownlinked data. \n\nBurst Advocate for this burst is S. B. Cenko (brad.cenko AT 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": 15384,
  "createdOn": 1382771034000,
  "email": "palmer@lanl.gov",
  "subject": "Swift Trigger 575905: a possible GRB",
  "submitter": "David Palmer at LANL  <palmer@lanl.gov>"
}