{
  "bibcode": "2018GCN.22556....1R",
  "body": "J. L. Racusin (NASA/GSFC), A. Deich (PSU), J. A. Kennea (PSU),\nH. A. Krimm (NSF/USRA), K. L. Page (U Leicester), D. M. Palmer (LANL)\nand A. Tohuvavohu (PSU) report on behalf of the Neil Gehrels Swift\nObservatory Team:\n\nAt 00:58:00 UT, the Swift Burst Alert Telescope (BAT) triggered and\nlocated a marginal-significance (6.9 sigma) image peak that may be \nGRB 180329A (trigger=819301).  Swift could not slew to the location \ndue to an observing constraint. \nThe BAT on-board calculated location is \nRA, Dec 329.298, -15.071 which is \n   RA(J2000) = 21h 57m 11s\n   Dec(J2000) = -15d 04' 14\"\nwith an uncertainty of 3 arcmin (radius, 90% containment, including \nsystematic uncertainty).  The BAT light curve shows some variation\nconsistent with a ~8 second long GRB, however this variation\nis also consistent with the presence of the currently-active black hole\ntransient MAXI J1820+070 in the FOV.  The peak count rate\nwas ~1400 counts/sec (15-350 keV), at ~5 sec after the trigger. \n\nDue to a Sun observing constraint, Swift cannot slew to the BAT\nposition until 23:07 UT on 2018 April 02. There will thus be no XRT or\nUVOT data for this trigger before this time. \n\nDue to the low significance of this detection, the presence of\na bright variable X-ray source in the BAT Field of View, and the lack\nof follow-up observations from the XRT and UVOT, we cannot determine\nwhether this is a GRB at this time.  Further analysis of the\nfull downlinked data will be required to decide if this is a\nGRB or a statistical fluctuation in the image plane. \n\nBurst Advocate for this burst is J. L. Racusin (judith.racusin 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": 22556,
  "createdOn": 1522286264000,
  "email": "palmer@lanl.gov",
  "subject": "Swift Trigger 819301: possible GRB 180329A",
  "submitter": "David Palmer at LANL  <palmer@lanl.gov>",
  "eventId": "GRB 180329A"
}