{
  "eventId": "GRB 231117A",
  "subject": "GRB 231117A: Swift detection of a bright short burst",
  "circularId": 35071,
  "body": "\nS. Laha (GSFC/UMBC), C. Gronwall (PSU), J.D. Gropp (PSU),\nN. J. Klingler (GSFC/UMBC/CRESSTII), D. M. Palmer (LANL),\nT. M. Parsotan (GSFC/UMBC/CRESSTII), C. Salvaggio (INAF-OAB) and\nA. Tohuvavohu (U Toronto) report on behalf of the Neil Gehrels Swift\nObservatory Team:\n\nAt 03:03:19 UT, the Swift Burst Alert Telescope (BAT) triggered and\nlocated GRB 231117A (trigger=1197027).  Swift slewed immediately to the burst. \nThe BAT on-board calculated location is \nRA, Dec 332.409, +13.514 which is \n   RA(J2000) = 22h 09m 38s\n   Dec(J2000) = +13d 30' 49\"\nwith an uncertainty of 3 arcmin (radius, 90% containment, including \nsystematic uncertainty).  The BAT light curve showed a single bright\npeak structure with a duration of about 1.5 sec.  The peak count rate\nwas ~80,000 counts/sec (15-350 keV), at ~0 sec after the trigger. \n\nThe XRT began observing the field at 03:05:01.5 UT, 101.8 seconds after\nthe BAT trigger. Using promptly downlinked data we find an uncatalogued\nX-ray source located at RA, Dec 332.39146, 13.52328 which is equivalent\nto:\n   RA(J2000)  = 22h 09m 33.95s\n   Dec(J2000) = +13d 31' 23.8\"\nwith an uncertainty of 4.3 arcseconds (radius, 90% containment). This\nlocation is 69 arcseconds from the BAT onboard position, within the BAT\nerror circle. This position may be improved as more data are received;\nthe latest position is available at https://www.swift.ac.uk/sper.  We\ncannot determine whether the source is fading at the present time. No\nspectrum from the promptly downlinked event data is yet available to\ndetermine the column density. \n\nUVOT took a finding chart exposure of 150 seconds with the White filter\nstarting 105 seconds after the BAT trigger. No credible afterglow candidate has\nbeen found in the initial data products. The 2.7'x2.7' sub-image processing\nFAILED because of no aspect solution. Results from the list of sources\ngenerated on-board are not available at this time. No correction has been made\nfor the expected extinction corresponding to E(B-V) of 0.071. \n\nBurst Advocate for this burst is S. Laha (sib.laha 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/)\n\n",
  "createdOn": 1700190998521,
  "submittedHow": "email",
  "bibcode": "2023GCN.35071....1L",
  "submitter": "David Palmer at LANL <palmer@lanl.gov>"
}