{
  "bibcode": "2006GCN..5519....1O",
  "body": "S. R. Oates (UCL-MSSL), D. Grupe (PSU) on behalf of the Swift UVOT team\n\nThe Swift Ultra-Violet/Optical Telescope (UVOT) began observations of \nGRB060904b at 02:32:14 UT, ~71 seconds after the initial Swift BAT trigger\n(Grupe et al, GCN 5505). An optical counterpart was detected with the\nV filter at a position RA(J2000)= (03h,52m,50.54s, -00o43'31.1'') to within 0.5''.\nAn optical afterglow was detected in V, B, U, UVW1, UVM2 and UVW2 filters.\n\nThe photometery results are given for the 6 filters below:\n\nFilter      Tstart  Tstop   Magnitudes and UL\n---------------------------------------------\nV             71    316      18.64 +/-  0.33\n              4732   4931     19.16 +/-  0.36\n              5960   6100     18.25 3 sigma UL\n\nB            4322   4521     18.98 +/-  0.15\n              5550   5749     19.56 +/-  0.28\n\nU            4117   4316     18.32 +/-  0.19\n              5346   5545     18.65 +/-  0.23\n\nUVW1         3913   4112     18.78 +/-  0.31\n              5141   5340     19.11 +/-  0.36\n\nUVM2         3708   3907     18.88 +/-  0.36\n              4936   5135     19.66 +/-  0.55\n\nUVW2         4528   4727     18.96 +/-  0.33\n              5756   5955     19.32 +/-  0.41\n---------------------------------------------\n\nThe values quoted above are not corrected for the expected\nGalactic extinction of E_{B-V}=0.173.",
  "circularId": 5519,
  "createdOn": 1157381410000,
  "email": "sro@mssl.ucl.ac.uk",
  "subject": "GRB060904b: Optical observations with Swift/UVOT",
  "submitter": "Samantha Oates at MSSL  <sro@mssl.ucl.ac.uk>",
  "eventId": "GRB 060904B"
}