{
  "bibcode": "2018GCN.22335....1C",
  "body": "J. K. Cannizzo (NASA/UMBC), J. R. Cummings (NASA/UMBC),\nA. D'Ai (INAF-IASFPA), V. D'Elia (ASDC), A. Deich (PSU),\nD. M. Palmer (LANL) and M. H. Siegel (PSU) report on behalf of the\nNeil Gehrels Swift Observatory Team:\n\nAt 04:16:03 UT, the Swift Burst Alert Telescope (BAT) triggered and\nlocated GRB 180115A (trigger=805318).  Swift slewed immediately to the burst. \nThe BAT on-board calculated location is \nRA, Dec 12.073, -15.608 which is \n   RA(J2000) = 00h 48m 18s\n   Dec(J2000) = -15d 36' 27\"\nwith an uncertainty of 3 arcmin (radius, 90% containment, including \nsystematic uncertainty).  As is usual for an image trigger, the\nimmediately available light curve shows no obvious variation. \n\nThe XRT began observing the field at 04:18:14.7 UT, 131.1 seconds after\nthe BAT trigger. Using promptly downlinked data we find a bright,\nuncatalogued X-ray source located at RA, Dec 12.03953, -15.62924 which\nis equivalent to:\n   RA(J2000)  = 00h 48m 09.49s\n   Dec(J2000) = -15d 37' 45.3\"\nwith an uncertainty of 3.8 arcseconds (radius, 90% containment). This\nlocation is 138 arcseconds from the BAT onboard position, within the\nBAT error circle. This position may be improved as more data are\nreceived; the latest position is available at\nhttp://www.swift.ac.uk/sper.  We cannot determine whether the source is\nfading at the present time. No spectrum from the promptly downlinked\nevent data is yet available to determine the column density. \n\nThe initial flux in the 2.5 s image was 3.57e-10 erg cm^-2 s^-1 (0.2-10\nkeV). \n\nUVOT took a finding chart exposure of 150 seconds with the White filter\nstarting 140 seconds after the BAT trigger. There is a candidate afterglow in\nthe rapidly available 2.7'x2.7' sub-image at\n  RA(J2000)  =\t00:48:09.25 =  12.03856\n  DEC(J2000) = -15:37:49.8  = -15.63051\nwith a 90%-confidence error radius of about 0.75 arc sec. This position is 5.6\narc sec. from the center of the XRT error circle. The estimated magnitude is\n17.54 with a 1-sigma error of about  0.14. No correction has been made for the\nexpected extinction corresponding to E(B-V) of 0.02. \n\nBurst Advocate for this burst is J. K. Cannizzo (cannizzo 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": 22335,
  "createdOn": 1515990442000,
  "email": "palmer@lanl.gov",
  "subject": "GRB 180115A: Swift detection of a burst with an optical counterpart.",
  "submitter": "David Palmer at LANL  <palmer@lanl.gov>",
  "eventId": "GRB 180115A"
}