{
  "bibcode": "2006GCN..5523....1O",
  "body": "S.R. Oates (UCL-MSSL), D. Grupe (PSU) report on behalf of the \nSwift/UVOT team:\n\nThe Swift/UVOT began observing the field of GRB 060904A at\n01:04:36 on 2006-09-04, 75 s after the BAT trigger (Grupe\net al., GCN 5502). No new source was detected within the XRT error \ncircle\nin coadded images in any filter down to the following 3-sigma\nmagnitude upper limits:\n\n\nFilter  Tstart   Tstop   Exposure  3-sigma UL\n-------------------------------------------------\nV        55       1888     1680    20.11\n\nB        658      1984     97      19.85\n\nU        634      1959     117     19.49\n\nUVW1     610      1936     117     19.91\n\nUVM2     586      1911     117     19.95\n\nUVW2     687      2014     128     20.55\n\nWhite    75       1997     352.2   21.69\n------------------------------------------------\n\nThese upper limits are not corrected for Galactic extinction\nE(B-V) = 0.018.",
  "circularId": 5523,
  "createdOn": 1157398016000,
  "email": "sro@mssl.ucl.ac.uk",
  "subject": "GRB060904A:  Swift/UVOT optical observations",
  "submitter": "Samantha Oates at MSSL  <sro@mssl.ucl.ac.uk>",
  "eventId": "GRB 060904A"
}