{
  "bibcode": "2014GCN.15695....1B",
  "body": "S. D. Barthelmy (GSFC), M. M. Chester (PSU), V. D'Elia (ASDC),\nD. Malesani (DARK/NBI), B. Sbarufatti (INAF-OAB/PSU) and\nB.-B. Zhang (UAH) report on behalf of the Swift Team:\n\nAt 23:21:08 UT, the Swift Burst Alert Telescope (BAT) triggered and\nlocated KS_1947+300 (trigger=583105).  Swift slewed immediately to the source. \nThe BAT on-board calculated location is \nRA, Dec 297.350, +30.231 which is \n   RA(J2000)  =  19h 49m 24s\n   Dec(J2000) = +30d 13' 52\"\nwith an uncertainty of 3 arcmin (radius, 90% containment, including \nsystematic uncertainty).  This is a very low significance image trigger. \n\nThe XRT began observing the field at 23:36:42.6 UT, 934.1 seconds after\nthe BAT trigger. Using promptly downlinked data we find a bright X-ray\nsource located at RA, Dec 297.39826, 30.20855 which is equivalent to:\n   RA(J2000)  = 19h 49m 35.58s\n   Dec(J2000) = +30d 12' 30.8\"\nwith an uncertainty of 3.7 arcseconds (radius, 90% containment). This\nlocation is 170 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 1.5 arcseconds from that\nof known X-ray source KS 1947+300. No event data are yet available to\ndetermine the column density using X-ray spectroscopy. \n\nA power-law fit to a spectrum formed from promptly downlinked event\ndata gives a column density consistent with the Galactic value of 8.90\nx 10^21 cm^-2 (Kalberla et al. 2005). \n\nThe initial flux in the 2.5 s image was 5.46e-10 erg cm^-2 s^-1 (0.2-10\nkeV). \n\nUVOT took a finding chart exposure of nominal 150 seconds with the \nWhite  filter starting 942 seconds after the BAT trigger. The initial\nimages are consistent with the identification of the source as KS\n1947+300.  Because of the  density of catalogued stars and the large\nbut uncertain extinction in the direction of the source, further\nanalysis is required to report photometric measurements. \n\nThe GCN notices were the result of a known race condition in the BAT\non-board software causing a misidentification of the source. \nThe ground processing correctly identified the source as \nKS 1947+300, which is currently in outburst (Kawagoe et al.,\nATEL #5438) and is continually seen by BAT (see\nhttp://swift.gsfc.nasa.gov/results/transients/weak/KS1947p300/\nfor the current light curve).",
  "circularId": 15695,
  "createdOn": 1389053179000,
  "email": "scott@milkyway.gsfc.nasa.gov",
  "subject": "Swift-BAT triggered on KS 1947+300",
  "submitter": "Scott Barthelmy at NASA/GSFC  <scott@milkyway.gsfc.nasa.gov>"
}