GCN Circular 13598

C. A. Swenson (PSU) and E. Troja (NASA/GSFC/ORAU)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 120805A
127 s after the BAT trigger (Troja et al., GCN Circ. 13588
Not found
 
 
).
No optical afterglow consistent with the refined XRT position (Burrows
et al., GCN Circ. 13592
Not found
 
 
) is detected in the initial UVOT exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the initial 
exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

white              127         7557          579         >22.0
v                 1339        11924         1248         >20.8
b                 1265         7352          490         >21.5
u                 1240         7146          490         >20.5
w1                1216        13611         1253         >21.3
m2                1364        12829         1141         >21.6
w2                1487         7763          432         >21.6

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.03 in the direction of the burst
(Schlegel et al. 1998).