{
  "bibcode": "2005GCN..3186....1R",
  "body": "E. Rol (University Leicester), P. Schady (MSSL/PSU), S. Hunsberger (PSU), A. \nBreeveld (MSSL), P. Boyd (GSFC/UMBC), C. Kouveliotou (MSFC), P. Roming (PSU),\nJ. Nousek (PSU), N. Gehrels (GSFC), on behalf of the Swift UVOT team.\n\nStarting with data taken 88 s after the BAT trigger (Parsons et al; GCN 3180),\nwe have co-added the early time data of GRB 050406 in each of the Swift\nUltra-Violet/Optical Telescope (UVOT) U, B, and V bands. We detect a source\nwithin the XRT error circle (M. Capalbi et al; GCN 3184) at the 4.3 (19.0\nmagnitude), 3.0, and 2.5-sigma detection levels in the U, B, and V\nrespectively. We do not detect a source in a second deeper U band observation\ntaken 1.3 hours after the burst. The source is located at RA = 02:17:52.2, DEC\n= -50:11:15.8. The UVOT source location and fading is consistent with the\nMagellan candidate by Berger et al (GCN 3185) strongly suggesting that this is\nthe optical counterpart of XRF 050406. More detailed analysis of the UVOT data\nis underway.",
  "circularId": 3186,
  "createdOn": 1112836793000,
  "email": "roming@astro.psu.edu",
  "subject": "Swift-UVOT Optical Counterpart Candidate to XRF 050406",
  "submitter": "Pete Roming at PSU  <roming@astro.psu.edu>"
}