{
  "bibcode": "2023GCN.33176....1S",
  "body": "E. Sonbas (Adiyaman Univ.), R. A. J. Eyles-Ferris (U Leicester),\nC. Gronwall (PSU), J.D. Gropp (PSU),\nN. J. Klingler (GSFC/UMBC/CRESSTII), S. Laha (GSFC/UMBC),\nA. Y. Lien (U Tampa), K. L. Page (U Leicester), D. M. Palmer (LANL),\nT. Sakamoto (AGU) and M. A. Williams (PSU) report on behalf of the\nNeil Gehrels Swift Observatory Team:\n\nAt 21:04:43 UT, the Swift Burst Alert Telescope (BAT) triggered and\nlocated GRB 230116D (trigger=1149293).  Swift slewed immediately to the burst. \nThe BAT on-board calculated location is \nRA, Dec 98.594, 49.840d which is \n   RA(J2000) = 06h 34m 23s\n   Dec(J2000) =  +49d 50' 24\"\nwith an uncertainty of 3 arcmin (radius, 90% containment, including \nsystematic uncertainty).  Due to a communications gap the BAT\nlightcurve before T+8 s is not immediately available, but\nthe later lightcurve indicates activity out to at least T+30 s. \n\nThe XRT began observing the field at 21:06:54.1 UT, 130.9 seconds after\nthe BAT trigger. Using promptly downlinked data we find an uncatalogued\nX-ray source with an enhanced position: RA, Dec 98.61709, 49.87257\nwhich is equivalent to:\n   RA(J2000)  = 06h 34m 28.10s\n   Dec(J2000) = +49d 52' 21.3\"\nwith an uncertainty of 1.9 arcseconds (radius, 90% containment). This\nlocation is 128 arcseconds from the BAT onboard position, within the\nBAT error circle. This position may be improved as more data are\nreceived; the latest position is available at\nhttps://www.swift.ac.uk/sper. \n\nA power-law fit to a spectrum formed from promptly downlinked event\ndata gives a column density consistent with the Galactic value of 1.65\nx 10^21 cm^-2 (Willingale et al. 2013). \n\nUVOT took a finding chart exposure of 150 seconds with the White filter\nstarting 133 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 0.112. \n\nBurst Advocate for this burst is E. Sonbas (edasonbas AT yahoo.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": 33176,
  "createdOn": 1673904205000,
  "email": "palmer@lanl.gov",
  "subject": "GRB 230116D: Swift detection of a burst",
  "submitter": "David Palmer at LANL  <palmer@lanl.gov>",
  "eventId": "GRB 230116D"
}