{
  "subject": "Swift Trigger 796098 is probably a noise peak near M31",
  "bibcode": "2017GCN.22212....1D",
  "createdOn": 1512831778000,
  "circularId": 22212,
  "submitter": "David Palmer at LANL  <palmer@lanl.gov>",
  "email": "palmer@lanl.gov",
  "body": "P. D'Avanzo (INAF-OAB), J.D. Gropp (PSU), J. A. Kennea (PSU),\nS. J. LaPorte (PSU), A. Y. Lien (GSFC/UMBC), A. Melandri (INAF-OAB)\nand D. M. Palmer (LANL) report on behalf of the Swift Team:\n\nAt 14:29:45 UT on 2017-09-17, the Swift Burst Alert Telescope (BAT) was \nobserving the bright source Swift J0243.6+6124 .  The pulsations from \nthis bright source cause BAT to trigger and image continuously while \nit is in the FOV. In one of these images, there was a low-significance \n(5.97 sigma) peak in the image within the boundaries of M31.  \n\nThe BAT on-board software has lowered thresholds in the regions around nearby \ngalaxies. As a result, BAT reported this image peak and attempted an automated\nfollow-up.  Due to the Earth limb constraint, Swift could not immediately\nobserve the location. \nThe BAT on-board calculated location is \nRA, Dec 12.177, +40.635 which is \n   RA(J2000) = 00h 48m 42s\n   Dec(J2000) = +40d 38' 07\"\nwith an uncertainty of 3 arcmin (radius, 90% containment, including \nsystematic uncertainty). \n\nWe do not believe this is a true source.  We may make follow-up observations\nwith XRT as time permits to verify that this.  However, this will be of\nlower priority than GRB 171209A which occurred a few minute later."
}