{
  "bibcode": "2022GCN.31468....1M",
  "body": "A. Melandri (INAF-OAB), M. G. Bernardini (INAF-OAB), J.D. Gropp (PSU),\nN. J. Klingler (GSFC/UMBC/CRESSTII), A. Y. Lien (U Tampa),\nF. E. Marshall (NASA/GSFC), D. M. Palmer (LANL),\nT. M. Parsotan (GSFC/UMBC/CRESSTII), T. Sbarrato (INAF-OAB) and\nM. H. Siegel (PSU) report on behalf of the Neil Gehrels Swift\nObservatory Team:\n\nAt 20:05:28 UT, the Swift Burst Alert Telescope (BAT) triggered and\nlocated GRB 220117B (trigger=1093611).  Swift slewed immediately to the burst. \nThe BAT on-board calculated location is \nRA, Dec 191.947, -28.744 which is \n   RA(J2000) = 12h 47m 47s\n   Dec(J2000) = -28d 44' 38\"\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 20 sec.  The peak count rate\nwas ~1000 counts/sec (15-350 keV), at ~1 sec after the trigger. \n\nThe XRT began observing the field at 20:07:04.0 UT, 95.9 seconds after\nthe BAT trigger. XRT found a bright, uncatalogued X-ray source located\nat RA, Dec 191.9514, -28.7446 which is equivalent to:\n   RA(J2000)  = 12h 47m 48.34s\n   Dec(J2000) = -28d 44' 40.6\"\nwith an uncertainty of 6.5 arcseconds (radius, 90% containment). This\nlocation is 14 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 4.69e-10 erg cm^-2 s^-1 (0.2-10\nkeV). \n\nUVOT took a finding chart exposure of nominal 150.000 seconds with the White\nfilter starting 104 seconds after the BAT trigger. No credible afterglow\ncandidate has been found in the initial data products. Data from the 2.7'x2.7'\nsub-image are not available at this time. The 8'x8' region for the list of\nsources generated on-board covers 100% of the XRT error circle. The list of\nsources is typically complete to about 18 mag. No correction has been made for\nthe expected extinction corresponding to E(B-V) of 0.075. \n\nBurst Advocate for this burst is A. Melandri (andrea.melandri AT brera.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": 31468,
  "createdOn": 1642450709000,
  "email": "palmer@lanl.gov",
  "subject": "GRB 220117B: Swift detection of a burst",
  "submitter": "David Palmer at LANL  <palmer@lanl.gov>",
  "eventId": "GRB 220117B"
}