{
  "bibcode": "2015GCN.17354....1D",
  "body": "P. D'Avanzo (INAF-OAB), P. A. Evans (U Leicester), J. A. Kennea (PSU)\nand A. Y. Lien (GSFC/UMBC) report on behalf of the Swift Team:\n\nAt 11:25:54 UT, the Swift Burst Alert Telescope (BAT) triggered (trigger=628458). \nSwift slewed immediately to the burst.  This was a sub-threshold image trigger \nspatially coincident with the galaxy NGC 4570. \nThe BAT on-board calculated location is \nRA, Dec 189.211, +7.330 which is \n   RA(J2000) = 12h 36m 51s\n   Dec(J2000) = +07d 19' 47\"\nwith an uncertainty of 3 arcmin (radius, 90% containment, including \nsystematic uncertainty).  As is usual with an image trigger, the available\nBAT light curve shows no significant structure. \n\nThe XRT began observing the field at 11:37:57.7 UT, 722.9 seconds after\nthe BAT trigger. No source was detected in 606 s of promptly downlinked\ndata, which covered 90% of the BAT error circle. We are waiting for the\nfull dataset to detect and localise the XRT counterpart. \n\nUVOT took a finding chart exposure of 150 seconds with the White filter\nstarting 726 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\n0.02.",
  "circularId": 17354,
  "createdOn": 1422359539000,
  "email": "kennea@swift.psu.edu",
  "subject": "Swift Trigger 628458 likely not astrophysical",
  "submitter": "Jamie A. Kennea at PSU/Swift-XRT  <kennea@swift.psu.edu>"
}