{
  "bibcode": "2022GCN.32060....1G",
  "body": "J.D. Gropp (PSU), K. L. Page (U Leicester),\nT. M. Parsotan (GSFC/UMBC/CRESSTII), B. Sbarufatti (PSU) and\nM. H. Siegel (PSU) report on behalf of the Neil Gehrels Swift\nObservatory Team:\n\nAt 06:19:20 UT, the Swift Burst Alert Telescope (BAT) triggered and\nlocated GRB 220518A (trigger= 1107050).  Swift slewed immediately to the burst. \nThe BAT on-board calculated location is \nRA, Dec 55.369, -47.571 which is \n   RA(J2000) = +03h 41m 29s\n   Dec(J2000) = -47d 34' 15\"\nwith an uncertainty of 3 arcmin (radius, 90% containment, including \nsystematic uncertainty).  There are currently no BAT light curve data available\nat this time. \n\nThe XRT began observing the field at 06:21:27.1 UT, 126.4 seconds after\nthe BAT trigger. Using promptly downlinked data we find an uncatalogued\nX-ray source with an enhanced position: RA, Dec 55.34297, -47.58392\nwhich is equivalent to:\n   RA(J2000)  = 03h 41m 22.31s\n   Dec(J2000) = -47d 35' 02.1\"\nwith an uncertainty of 1.9 arcseconds (radius, 90% containment). This\nlocation is 78 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 (9.33 x\n10^19 cm^-2, Willingale et al. 2013), with an excess column of 5\n(+3.25/-2.72) x 10^21 cm^-2 (90% confidence). \n\nUVOT took a finding chart exposure of 150 seconds with the White filter\nstarting 129 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 none of\nthe XRT error circle. The 8'x8' region for the list of sources generated\non-board covers 100% of the XRT error circle. The list of sources is typically\ncomplete to about 18 mag. No correction has been made for the expected\nextinction corresponding to E(B-V) of 0.008. \n\nBurst Advocate for this burst is J.D. Gropp (jdg44 AT psu.edu). \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": 32060,
  "createdOn": 1652856444000,
  "email": "kimlpage1978@gmail.com",
  "subject": "GRB 220518A: Swift detection of a burst",
  "submitter": "Kim Page at U.of Leicester  <kimlpage1978@gmail.com>",
  "eventId": "GRB 220518A"
}