{
  "circularId": 45690,
  "submitter": "K.L. Page at U Leicester <klp5@leicester.ac.uk>",
  "body": "K. L. Page (U Leicester), P. A. Evans (U Leicester) and\nA. Y. Lien (U Tampa) report on behalf of the Neil Gehrels Swift\nObservatory Team:\n\nAt 10:00:39.44 UT, the Swift Burst Alert Telescope (BAT) triggered and\nlocated GRB 260922A (trigger=1512686).  Swift slewed immediately to the\nburst.\nThe BAT on-board calculated location is\nRA, Dec = 227.904, +14.207 deg,  which is\n   RA(J2000) = 15h 11m 37s\n   Dec(J2000) = 14d 12' 26\"\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 50 sec.  The peak count rate\nwas ~3000 counts/sec (15-350 keV), at ~1 sec after the trigger.\n\nThe XRT began observing the field at 10:02:28.3 UT, 108.9 seconds after\nthe BAT trigger. Using promptly downlinked data we find a bright,\nfading, uncatalogued X-ray source with an enhanced position: RA, Dec\n227.90885, 14.21924 which is equivalent to:\n   RA(J2000)  = 15h 11m 38.12s\n   Dec(J2000) = +14d 13' 09.3\"\nwith an uncertainty of 2.4 arcseconds (radius, 90% containment). This\nlocation is 47 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.\n\nA power-law fit to a spectrum formed from promptly downlinked event\ndata gives a column density in excess of the Galactic value (2.88 x\n10^20 cm^-2, Willingale et al. 2013), with an excess column of 5.1\n(+2.88/-2.57) x 10^21 cm^-2 (90% confidence).\n\nThe initial flux in the 2.5 s image was 2.31e-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 122 seconds after the BAT trigger. No credible afterglow\ncandidate has been found in the initial data products. The 2.7'x2.7'\nsub-image covers 100% of the XRT error circle. The typical 3-sigma upper\nlimit has been about 19.6 mag. The 8'x8' region for the list of sources\ngenerated 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\nfor extinction.\n\nBurst Advocate for this burst is K. L. Page (klp5 AT leicester.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/)\n",
  "createdOn": 1790072344719,
  "subject": "GRB 260922A: Swift detection of a burst",
  "eventId": "GRB 260922A",
  "submittedHow": "email"
}