{
  "bibcode": "2019GCN.24021....1K",
  "body": "J. A. Kennea (PSU), N. J. Klingler (PSU), A. Y. Lien (GSFC/UMBC),\nF. E. Marshall (NASA/GSFC), K. L. Page (U Leicester) and\nB. Sbarufatti (PSU) report on behalf of the Neil Gehrels Swift\nObservatory Team:\n\nAt 21:27:45 UT, the Swift Burst Alert Telescope (BAT) triggered and\nlocated GRO J2058+42 (trigger=895479).  Swift slewed immediately to the source. \nThe BAT on-board calculated location is \nRA, Dec 314.705, +41.745 which is \n   RA(J2000) = 20h 58m 49s\n   Dec(J2000) = +41d 44' 41\"\nwith an uncertainty of 3 arcmin (radius, 90% containment, including \nsystematic uncertainty).  As is usual with an image trigger, the available\nBAT light curve shows no significant structure. \n\nThe XRT began observing the field at 21:30:58.4 UT, 193.0 seconds after\nthe BAT trigger. Using promptly downlinked data we find an X-ray source\nwith an enhanced position: RA, Dec 314.6977, 41.7766 which is\nequivalent to:\n   RA(J2000)  = 20h 58m 47.44s\n   Dec(J2000) = +41d 46' 35.6\"\nwith an uncertainty of 2.5 arcseconds (radius, 90% containment). This\nlocation is 115 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\nhttp://www.swift.ac.uk/sper. This position is 2.3 arcseconds from a\nknown X-ray source: 1SXPS J205847.2+414637. This source is in the Swift\nXRT 1SXPS catalogue with a mean 0.3-10 keV count-rate of 1.350 +/-\n0.043 ct/sec; see http://www.swift.ac.uk/1SXPS/1SXPSJ205847.2%2B414637\nfor details of these previous observations. No spectrum from the\npromptly downlinked event data is yet available to determine the column\ndensity. \n\nUVOT took a finding chart exposure of 250 seconds with the U filter\nstarting  193 seconds after the BAT trigger. UVOT detects a 16th mag\nsource consistent with the XRT position. No  correction has been made\nfor the large, but uncertain, extinction expected. \n\nSwift-BAT previously triggered on this source on 2019 March 22 (GCN Circ. 23985)\nand earlier today on 2019 March 27 (GCN Circ. 24017)\n\nThe BAT transient monitor of this source shows the source to be in outburst: \nhttps://swift.gsfc.nasa.gov/results/transients/weak/GROJ2058p42/",
  "circularId": 24021,
  "createdOn": 1553723345000,
  "email": "klp5@leicester.ac.uk",
  "subject": "Swift Trigger 895479: Detection of GRO J2058+42",
  "submitter": "Kim Page at U.of Leicester  <klp5@leicester.ac.uk>"
}