{
  "bibcode": "2017GCN.20832....1L",
  "body": "A. Y. Lien (GSFC/UMBC), S. D. Barthelmy (GSFC), L. M. Z. Hagen (PSU),\nJ. A. Kennea (PSU), K. L. Page (U Leicester), D. M. Palmer (LANL),\nJ. L. Racusin (NASA/GSFC), B. Sbarufatti (INAF-OAB/PSU) and\nE. Troja (NASA/GSFC/UMCP) report on behalf of the Swift Team:\n\nAt 20:24:21 UT, the Swift Burst Alert Telescope (BAT) triggered and\nlocated the possible GRB 170307A (trigger=741528).  Swift did not slew\ndue to an observing constraint.  The BAT on-board calculated location is \nRA, Dec 13.535, +9.537, which is \n   RA(J2000)  =  00h 54m 08s\n   Dec(J2000) = +09d 32' 11\"\nwith an uncertainty of 3 arcmin (radius, 90% containment, including \nsystematic uncertainty).  The BAT light curve shows that Swift was \nemerging from the SAA at this time, giving a quickly-decreasing\ncount rate that would swamp any variation expected from the source\nat the nominal intensity implied by the image strength. \n\nDue to a Sun observing constraint, Swift cannot slew to the BAT\nposition until 00:33 UT on 2017 May 24. There will thus be no XRT or\nUVOT data for this trigger before this time. \n\nBecause of high and variable background rates from the SAA, and\nin the absence of follow-up observations by the XRT, the \nimmediately-available data does not determine whether this \nwas a true astronomical event or an image fluctuation \n(with a nominal significance of 7.2 sigma). \nA determination of the nature of this source will require the\nfull downlinked data set. \n\nBurst Advocate for this burst is A. Y. Lien (amy.y.lien 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": 20832,
  "createdOn": 1488919290000,
  "email": "palmer@lanl.gov",
  "subject": "Swift Trigger 741528: a possible GRB",
  "submitter": "David Palmer at LANL  <palmer@lanl.gov>"
}