{
  "bibcode": "2009GCN..9938....1G",
  "body": "C. Gronwall (PSU) and L. Vetere (PSU) report on behalf of the\nSwift/UVOT team:\n\nThe Swift/UVOT began settled observations of the field of GRB 090926A\napproximately 13 hours after the Fermi/GBM trigger (Bissaldi,\nGCN Circ. 9933).  In a 357 sec observation in the white filter, we\nfind a candidate optical afterglow within the XRT error circle (Vetere\net al., GCN Circ. 9936) at\n  RA(J2000) =  23:33:36.037 = 353.400154\n  Dec(J2000) = -66:19:26.64 = 66.324067\nwith a 90%-confidence error radius of about 0.11 arc sec. This position\nis 0.99 arc sec. from the center of the XRT error circle and is  \nconsistent\nwith the optical afterglow position found by Skynet/PROMPT (Haislip et\nal., GCN Circ. 9937).  The estimated magnitude is 18.78 +/- 0.04.\nThis value is not corrected for the Galactic extinction due to the\nreddening of E(B-V) = 0.03 in the direction of the burst\n(Schlegel et al. 1998).",
  "circularId": 9938,
  "createdOn": 1254017434000,
  "email": "caryl@astro.psu.edu",
  "subject": "GRB 090926A: Swift/UVOT detection of an optical afterglow",
  "submitter": "Caryl Gronwall at PSU/Swift-UVOT  <caryl@astro.psu.edu>",
  "eventId": "GRB 090926A"
}