{
  "bibcode": "2013GCN.14551....1C",
  "body": "J. R. Cummings (NASA/UMBC), S. D. Barthelmy (GSFC),\nW. H. Baumgartner (GSFC/UMBC), D. N. Burrows (PSU),\nP. D'Avanzo (INAF-OAB), V. D'Elia (ASDC), N. Gehrels (NASA/GSFC),\nJ. A. Kennea (PSU), H. A. Krimm (CRESST/GSFC/USRA),\nF. E. Marshall (NASA/GSFC), D. M. Palmer (LANL),\nB. Sbarufatti (INAF-OAB/PSU), M. H. Siegel (PSU),\nE. Troja (NASA/GSFC/UMCP) and T. N. Ukwatta (MSU) report on behalf of\nthe Swift Team:\n\nAt 02:05:34 UT, the Swift Burst Alert Telescope (BAT) triggered and\nlocated trigger=555096.  Swift slewed immediately to the transient. \nThe BAT on-board calculated location is \nRA, Dec 272.365, -16.344 which is \n   RA(J2000) = 18h 09m 27s\n   Dec(J2000) = -16d 20' 38\"\nwith an uncertainty of 3 arcmin (radius, 90% containment, including \nsystematic uncertainty).  The BAT light curve showed two FRED peaks\nwith a duration of about 25 sec.  The peak count rate was ~1617 counts/sec \n(15-350 keV), at ~2 sec after the trigger. \n\nThe XRT began observing the field at 02:07:00.2 UT, 85.9 seconds after\nthe BAT trigger. No source was detected in 1.1 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 88 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 large, but uncertain extinction expected. \n\nThe event is unusual in that it is a long burst in BAT with no \ndetected X-ray counterpart after an immediate slew.  We also note\nthat this location is in the Galactic bulge near the plane\n(lon = 13.65, lat=1.56).  Ground analysis of the detector\nplane histogram finds only a marginal image detection (5.9 sigma). \n\nFor these reasons, we will not be able to determine the reality\nor nature of this event until ground-linked data is available. \n\nBurst Advocate for this burst is J. R. Cummings (jayc 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": 14551,
  "createdOn": 1367634579000,
  "email": "palmer@lanl.gov",
  "subject": "Trigger 555096: Swift detection of a possible burst",
  "submitter": "David Palmer at LANL  <palmer@lanl.gov>"
}