{
  "bibcode": "2013GCN.15361....1D",
  "body": "P. D'Avanzo, A. Melandri, M. G. Bernardini (INAF-OAB), P. A. Evans (U. Leicester)\nreport on behalf of the Swift-XRT team:\n\nWe have analysed 2.8 ks of XRT data for the Fermi/LAT-detected burst:\nGRB 131018B (Vianello et al., GCN 15357; Zhang, GCN 15360),  from 83.1\nks to 95.2 ks after the  Fermi/LAT trigger. The data are entirely in\nPhoton Counting (PC) mode.  An uncatalogued X-ray source is detected\nwithin the Fermi/LAT error circle. The refined XRT position is RA, Dec\n= 304.53693, +23.18759 which is equivalent to:\n\nRA (J2000): 20 18 08.86\nDec(J2000): +23 11 15.3\n\nwith an uncertainty of 4.9 arcsec (radius, 90% confidence). This\nposition is 514 arcsec from the Fermi/LAT position.  We cannot\ndetermine at the present time whether the source is fading.\n\n\nWe note the presence of two further sources within the LAT error box.\n\nSource #2 has the following position RA, Dec = 304.41156, +23.16636\nwhich is equivalent to:\n\nRA (J2000): 20 17 38.77\nDec(J2000): +23 09 58.9\n\nwith an uncertainty of 5.4 arcsec (radius, 90% confidence). \n\nSource #3 has the following position RA, Dec = 304.52361 +23.06517\nwhich is equivalent to:\n\nRA (J2000): 20 18 05.67\nDec(J2000): +23 03 54.6\n\nwith an uncertainty of 6.0 arcsec (radius, 90% confidence). \n\nBoth sources are present in the Swift-XRT point source catalogue\n(D'Elia et al. 2013; A&A 551, A142) and are likely not related with GRB\n131018B. \n\n\nThe results of the XRT-team automatic analysis are available at\nhttp://www.swift.ac.uk/xrt_products/00020308.\n\nThis circular is an official product of the Swift-XRT team.\n\n[GCN OPS NOTE(22oct13): Per author's reuqest, the affiliations of the authors\nwas corrected.]",
  "circularId": 15361,
  "createdOn": 1382297714000,
  "email": "paolo.davanzo@brera.inaf.it",
  "subject": "GRB 131018B: Swift-XRT observations",
  "submitter": "Paolo D'Avanzo at INAF-OAB  <paolo.davanzo@brera.inaf.it>",
  "eventId": "GRB 131018B"
}