{
  "subject": "GRB 180905A: Swift detection of a burst",
  "eventId": "GRB 180905A",
  "bibcode": "2018GCN.23201....1D",
  "createdOn": 1536156452000,
  "circularId": 23201,
  "submitter": "David Palmer at LANL  <palmer@lanl.gov>",
  "email": "palmer@lanl.gov",
  "body": "V. D'Elia (SSDC), A. D'Ai (INAF-IASFPA), J.D. Gropp (PSU),\nJ. A. Kennea (PSU), M. J. Moss (George Washington University),\nK. L. Page (U Leicester), D. M. Palmer (LANL) and B. Sbarufatti (PSU)\nreport on behalf of the Neil Gehrels Swift Observatory Team:\n\nAt 13:57:46 UT, the Swift Burst Alert Telescope (BAT) triggered and\nlocated GRB 180905A (trigger=859421).  Swift slewed immediately to the burst. \nThe BAT on-board calculated location is \nRA, Dec 91.035, -4.591 which is \n   RA(J2000) = 06h 04m 08s\n   Dec(J2000) = -04d 35' 27\"\nwith an uncertainty of 3 arcmin (radius, 90% containment, including \nsystematic uncertainty).  As is usual for an image trigger, no obvious\nvariation is visible in the immediately-available lightcurve. \n\nThe XRT began observing the field at 14:00:12.3 UT, 145.9 seconds after\nthe BAT trigger. XRT found a bright, uncatalogued X-ray source located\nat RA, Dec 91.0602, -4.5724 which is equivalent to:\n   RA(J2000)  = 06h 04m 14.45s\n   Dec(J2000) = -04d 34' 20.6\"\nwith an uncertainty of 5.1 arcseconds (radius, 90% containment). This\nlocation is 112 arcseconds from the BAT onboard position, within the\nBAT error circle. No event data are yet available to determine the\ncolumn density using X-ray spectroscopy. \n\nThe initial flux in the 2.5 s image was 2.03e-09 erg cm^-2 s^-1 (0.2-10\nkeV). \n\nUVOT took a finding chart exposure of 135 seconds with the White filter\nstarting 153 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 100% of\nthe XRT error circle. The typical 3-sigma upper limit has been about 19.6 mag. \nThe 8'x8' region for the list of sources generated on-board covers 100% of the\nXRT error circle. The list of sources is typically complete to about 18 mag. No\ncorrection has been made for the expected extinction corresponding to E(B-V) of\n0.60. \n\nBurst Advocate for this burst is V. D'Elia (delia AT ssdc.asi.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/too.html.)"
}