{
  "bibcode": "2019GCN.26108....1A",
  "body": "E. Ambrosi (INAF-IASFPA), A. D'Ai (INAF-IASFPA), J.D. Gropp (PSU),\nN. J. Klingler (PSU), H. A. Krimm (NSF), S Laha (GSFC/UMBC/CRESST),\nF. E. Marshall (NASA/GSFC), K. L. Page (U Leicester) and\nD. M. Palmer (LANL) report on behalf of the Neil Gehrels Swift\nObservatory Team:\n\nAt 18:43:54 UT, the Swift Burst Alert Telescope (BAT) triggered and\nlocated GRB 191031C (trigger=932595).  Swift slewed immediately to the burst. \nThe BAT on-board calculated location is \nRA, Dec 115.862, -62.335 which is \n   RA(J2000) = 07h 43m 27s\n   Dec(J2000) = -62d 20' 04\"\nwith an uncertainty of 3 arcmin (radius, 90% containment, including \nsystematic uncertainty).  The BAT light curve showed a multi-peaked\nstructure with a duration of about 80 sec.  The peak count rate\nwas ~2400 counts/sec (15-350 keV), at ~4 sec after the trigger. \n\nThe XRT began observing the field at 18:45:16.2 UT, 81.3 seconds after\nthe BAT trigger. XRT found a bright, uncatalogued X-ray source located\nat RA, Dec 115.8682, -62.3247 which is equivalent to:\n   RA(J2000)  = 07h 43m 28.37s\n   Dec(J2000) = -62d 19' 28.9\"\nwith an uncertainty of 5.0 arcseconds (radius, 90% containment). This\nlocation is 38 arcseconds from the BAT onboard position, within the BAT\nerror circle. No event data are yet available to determine the column\ndensity using X-ray spectroscopy. \n\nThe initial flux in the 2.5 s image was 2.60e-09 erg cm^-2 s^-1 (0.2-10\nkeV). \n\nUVOT took a finding chart exposure of 150 seconds with the White filter\nstarting 90 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 100% of\nthe XRT 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\nXRT 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\n0.17. \n\nBurst Advocate for this burst is E. Ambrosi (elena.ambrosi AT inaf.it). \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/)",
  "circularId": 26108,
  "createdOn": 1572548134000,
  "email": "palmer@lanl.gov",
  "subject": "GRB 191031C: Swift detection of a burst",
  "submitter": "David Palmer at LANL  <palmer@lanl.gov>",
  "eventId": "GRB 191031C"
}