{
  "bibcode": "2006GCN..4779....1M",
  "body": "F. Marshall (GSFC), S. Immler (GSFC/USRA) and G. Cusumano (IASF-Pa INAF)\nreport on behalf of the Swift team:\n\nThe UVOT source reported by Cusumano et al. (GCN 4775) is detected in all\nfour UVOT finding chart exposures ranging from 153s to 1036s\nfrom the burst trigger as shown in the table below. There is marginal\nevidence for brightening in the V filter. The revised source position is\n03:21:39.71 +16:52:02.6 (J2000) with an estimated 1-sigma error of about 1.0\".\nThis position is within the XRT error circle (Kennea et al. GCN 4776).\nWe note the existence of a source in the USNO-B1 catalog\nat 03:21:39.69 +16:52:02.2 with a B2 magnitude of 20.67\nand an R2 magnitude of 20.3. Further UVOT observations\nare underway to search for fading of this afterglow candidate.\n\nT_start  Exposure   Filter   Mag   Mag. Range (1-sigma)\n 153       200       V      19.6    19.1 - 20.3\n 359       155       B      19.4    19.2 - 19.6\n 830       127       B      19.3    19.1 - 19.5\n1036       148       V      18.4    18.2 - 18.6",
  "circularId": 4779,
  "createdOn": 1140282088000,
  "email": "marshall@milkyway.gsfc.nasa.gov",
  "subject": "Further UVOT Observations of the Candidate Optical Afterglow for GRB 060218",
  "submitter": "Frank Marshall at GSFC  <marshall@milkyway.gsfc.nasa.gov>",
  "eventId": "GRB 060218"
}