GCN Circular 5519
Subject
GRB060904b: Optical observations with Swift/UVOT
Event
Date
2006-09-04T14:50:10Z (19 years ago)
From
Samantha Oates at MSSL  <sro@mssl.ucl.ac.uk>
S. R. Oates (UCL-MSSL), D. Grupe (PSU) on behalf of the Swift UVOT team
The Swift Ultra-Violet/Optical Telescope (UVOT) began observations of 
GRB060904b at 02:32:14 UT, ~71 seconds after the initial Swift BAT trigger
(Grupe et al, GCN 5505). An optical counterpart was detected with the
V filter at a position RA(J2000)= (03h,52m,50.54s, -00o43'31.1'') to within 0.5''.
An optical afterglow was detected in V, B, U, UVW1, UVM2 and UVW2 filters.
The photometery results are given for the 6 filters below:
Filter      Tstart  Tstop   Magnitudes and UL
---------------------------------------------
V             71    316      18.64 +/-  0.33
              4732   4931     19.16 +/-  0.36
              5960   6100     18.25 3 sigma UL
B            4322   4521     18.98 +/-  0.15
              5550   5749     19.56 +/-  0.28
U            4117   4316     18.32 +/-  0.19
              5346   5545     18.65 +/-  0.23
UVW1         3913   4112     18.78 +/-  0.31
              5141   5340     19.11 +/-  0.36
UVM2         3708   3907     18.88 +/-  0.36
              4936   5135     19.66 +/-  0.55
UVW2         4528   4727     18.96 +/-  0.33
              5756   5955     19.32 +/-  0.41
---------------------------------------------
The values quoted above are not corrected for the expected
Galactic extinction of E_{B-V}=0.173.