TITLE:   GCN CIRCULAR
NUMBER:  6036
SUBJECT: GRB 070125: UVOT Observations of a Fading Optical Afterglow
DATE:    07/01/26 17:20:23 GMT
FROM:    Frank Marshall at GSFC  <marshall@milkyway.gsfc.nasa.gov>

F. E. Marshall (NASA/GSFC) and J. Racusin (PSU) report on behalf
of the Swift team:

Swift/UVOT observed the field of GRB 070125 (Hurley et al., GCN Circ. 6024)
starting 13 hours after the burst. A bright, fading source
at the position reported by Cenko (GCN Circ. 6034)
is detected with the V and B filters. Additional observations
are now being taken with the other UVOT filters.

The table below gives the measured magnitudes for the currently
available data. T_start and T_end are the start and stop
times of the summed exposures in seconds from the trigger.
No correction has been made for the expected
Galactic reddening of E(B-V) = 0.05.

Filter  T_start   T_end  Exposure  Mag   Error
V       46685     53261   1736    18.54  0.06
V       58269     63986   1590    18.74  0.07
B       47550     54163   1674    18.92  0.03
B       59126     59947    798    19.03  0.06