{
  "bibcode": "2017GCN.21168....1G",
  "body": "J.D. Gropp (PSU), M.H. Siegel (PSU), J.A. Kennea (PSU), A.\nCholden-Brown (PSU) reporting on behalf of the Swift team.\n\n\nThe Swift-UVOT and XRT began settled observations of the field of GRB\n170524B 120 ks after the\n\nBAT trigger (Barthelmy et al., GCN Circ. 21142). A fading source\nconsistent with the XRT position\n\nis detected in the UVOT exposures.\n\nSwift-XRT performed follow-up observations of the\nSwift/BAT-detected burst GRB 170524B (Barthelmy et al. GCN Circ.21142),\ncollecting an additional 3ks (5.1 total) of Photon Counting (PC) mode data.\n\nOne uncatalogued X-ray source has been detected consistent with being\nwithin 296 arcsec of the Swift/BAT position. There is also evidence of fading,\n\nwhich is confirmed with UVOT analysis.\n\nXRT light curve can be modeled with a power-law decay with a decay\nindex alpha = 1.3\n\n\nThe preliminary UVOT position is:\n    RA  (J2000) =  06:03:28.49 =  90.86872 (deg.)\n    Dec (J2000) = -17:04:58.7  = -17.08297 (deg.)\nwith an estimated uncertainty of 0.4 arc sec. (radius, 90% confidence).\n\nPreliminary detections using the UVOT photometric system\n(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early exposures are:\n\nFilter         T_start(s)   T_stop(s)      Exp(s)                  Mag\n\nwhite            120431        126833        1297          19.89+-0.08\nwhite            274703        286595        2027          21.11+-0.23\n\nThe magnitudes in the table are not corrected for the Galactic extinction\ndue to the reddening of E(B-V) = 0.19 in the direction of the burst.\n\nThe decay inferred from the UVOT white data suggests a slope of\napproximately -1.3.\n\nThis circular is an official product of the Swift team.",
  "circularId": 21168,
  "createdOn": 1496171255000,
  "email": "jdg44@psu.edu",
  "subject": "GRB 170524B: Swift-UVOT/XRT Confirmation of Afterglow",
  "submitter": "Jeffrey Gropp at PSU  <jdg44@psu.edu>",
  "eventId": "GRB 170524B"
}