{
  "bibcode": "2022GCN.32998....1T",
  "body": "E. Troja (NASA/GSFC/UMCP), M. G. Bernardini (INAF-OAB),\nR. Brivio (INAF-OAB), P. D'Avanzo (INAF-OAB), S. Dichiara (PSU),\nP. A. Evans (U Leicester), R. A. J. Eyles-Ferris (U Leicester),\nM. Ferro (INAF-OAB), J.D. Gropp (PSU), J. A. Kennea (PSU),\nF. E. Marshall (NASA/GSFC), A. Melandri (INAF-OAB),\nK. L. Page (U Leicester), D. M. Palmer (LANL),\nC. Salvaggio (INAF-OAB), T. Sbarrato (INAF-OAB) and\nB. Sbarufatti (INAF-OAB) report on behalf of the Neil Gehrels Swift\nObservatory Team:\n\nAt 12:25:05 UT, the Swift Burst Alert Telescope (BAT) triggered and\nlocated GRB 221201A (trigger=1142847).  Swift slewed immediately to the burst. \nThe BAT on-board calculated location is \nRA, Dec 266.933, -68.260 which is \n   RA(J2000) = 17h 47m 44s\n   Dec(J2000) = -68d 15' 33\"\nwith an uncertainty of 3 arcmin (radius, 90% containment, including \nsystematic uncertainty).  The BAT light curve showed a single peak\nstructure with a duration of about 40 sec.  The peak count rate \nwas ~5000 counts/sec (15-350 keV), at ~-13 sec after the trigger. \n(The peak occurred during a pre-planned slew and the nominal trigger\ntime is the start of the first post-slew image.)\n\nThe XRT began observing the field at 12:27:56.2 UT, 170.6 seconds after\nthe BAT trigger. XRT found a bright, uncatalogued X-ray source located\nat RA, Dec 266.9228, -68.2510 which is equivalent to:\n   RA(J2000)  = 17h 47m 41.47s\n   Dec(J2000) = -68d 15' 03.6\"\nwith an uncertainty of 5.7 arcseconds (radius, 90% containment). This\nlocation is 35 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 0.1 s image was 2.34e-08 erg cm^-2 s^-1 (0.2-10\nkeV). \n\nUVOT took a finding chart exposure of 202 seconds with the U filter starting\n337 seconds after the BAT trigger. No credible afterglow candidate has been\nfound in the initial data products. The 2.7'x2.7' sub-image covers 100% of the\nXRT error circle. The typical 3-sigma upper limit has been about 19.2 mag. Data\nfrom the list of sources generated on-board are not available at this time. No\ncorrection has been made for the expected extinction corresponding to E(B-V) of\n0.065. \n\nBurst Advocate for this burst is E. Troja (nora.gsfc AT gmail.com). \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": 32998,
  "createdOn": 1669898846000,
  "email": "pae9@leicester.ac.uk",
  "subject": "GRB 221201A: Swift detection of a burst",
  "submitter": "Phil Evans at U of Leicester  <pae9@leicester.ac.uk>",
  "eventId": "GRB 221201A"
}