{
  "bibcode": "2021GCN.31160....1E",
  "body": "P. A. Evans (U Leicester), S. Dichiara (PSU), J.D. Gropp (PSU) and\nK. L. Page (U Leicester) report on behalf of the Neil Gehrels Swift\nObservatory Team:\n\nAt 09:02:38 UT, the Swift Burst Alert Telescope (BAT) triggered and\nlocated GRB 211203A (trigger=1086826).  Swift slewed immediately to the burst. \nThe BAT on-board calculated location is \nRA, Dec 170.174, +16.256 which is \n   RA(J2000) = 11h 20m 42s\n   Dec(J2000) = +16d 15' 21\"\nwith an uncertainty of 3 arcmin (radius, 90% containment, including \nsystematic uncertainty).  The BAT light curve showed a complex\nstructure with a duration of about 25 sec.  The peak count rate\nwas ~3000 counts/sec (15-350 keV), at ~7 sec after the trigger. \n\nThe XRT began observing the field at 09:03:56.8 UT, 78.5 seconds after\nthe BAT trigger. No source was detected in 2 s of promptly downlinked\ndata, which covered 93% 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 81 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\n0.023. \n\nBurst Advocate for this burst is P. A. Evans (pae9 AT star.le.ac.uk). \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": 31160,
  "createdOn": 1638524000000,
  "email": "pae9@star.le.ac.uk",
  "subject": "GRB 211203A: Swift detection of a burst",
  "submitter": "Phil Evans at U of Leicester  <pae9@star.le.ac.uk>",
  "eventId": "GRB 211203A"
}