{
  "bibcode": "2016GCN.19590....1B",
  "body": "S. D. Barthelmy (GSFC), A. D'Ai (INAF-IASFPA), N. Gehrels (NASA/GSFC),\nC. Gronwall (PSU) and D. M. Palmer (LANL) report on behalf of the\nSwift Team:\n\nAt 13:54:30 UT, the Swift Burst Alert Telescope (BAT) triggered and\nlocated SGR 1935+2154 (trigger=701590).  Swift slewed immediately to the source. \nThe BAT on-board calculated location is \nRA, Dec 293.730, +21.884 which is \n   RA(J2000)  =  19h 34m 55s\n   Dec(J2000) = +21d 53' 03\"\nwith an uncertainty of 3 arcmin (radius, 90% containment, including \nsystematic uncertainty).  The BAT light curve shows a single spike\nwith a duration of about 0.3 sec.  The peak count rate\nwas ~416,000 counts/sec (15-350 keV), at ~0 sec after the trigger. \n\nThe XRT began observing the field at 13:56:19.8 UT, 108.9 seconds after\nthe BAT trigger. Using promptly downlinked data we find a\nX-ray source located at RA, Dec 293.73009, 21.89586 which is equivalent\nto:\n   RA(J2000)  = 19h 34m 55.22s\n   Dec(J2000) = +21d 53' 45.1\"\nwith an uncertainty of 4.1 arcseconds (radius, 90% containment). This is\nconsistent with the known source SGR 1935+2154.  This\nposition may be improved as more data are received; the latest position\nis available at http://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 (1.27 x\n10^22 cm^-2, Willingale et al. 2013), with an excess column of 6\n(+6.83/-4.97) x 10^22 cm^-2 (90% confidence). \n\nUVOT took a finding chart exposure of 150 seconds with the White filter\nstarting 112 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 large, but uncertain extinction expected.",
  "circularId": 19590,
  "createdOn": 1466950329000,
  "email": "scott@milkyway.gsfc.nasa.gov",
  "subject": "Trigger 701590: Swift detection of a bright outburst from SGR 1935+2154",
  "submitter": "Scott Barthelmy at NASA/GSFC  <scott@milkyway.gsfc.nasa.gov>",
  "eventId": "SGR 1935+2154"
}