GCN Circular 18046

N. P. M. Kuin (UCL-MSSL) and F. E. Marshall (NASA/GSFC)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 150722A
3238 s after the BAT trigger (Marshall et al., GCN Circ. 18042
Not found
 
 
).
No optical afterglow consistent with the XRT position (Evans et al.
GCN Circ. No. 18044) 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 first
finding chart (FC) exposure and subsequent exposures are:

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

white_FC          3238         3388          147         >20.6
white             3238         5442          541         >21.6
v                 4217         5791          333         >20.0
b                 3602         5237          393         >21.0
u                 3396         5031          393         >20.6
w1                4627         4827          197         >20.1
m2                4422         4622          197         >20.3
w2                4012         5647          393         >21.4

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.06 in the direction of the burst
(Schlegel et al. 1998).