GCN Circular 20177

A. A. Breeveld (UCL-MSSL), P. D'Avanzo (INAF-OAB) and S. W. K. Emery 
(UCL-MSSL) report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 161113A 61 
s after the BAT trigger (D'Avanzo et al., GCN Circ. 20172
Not found
 
 
).
No optical afterglow consistent with the XRT position (Evans et al. GCN 
Circ. 20174
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 first finding chart (FC) 
exposures and subsequent exposures are:

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

white_FC            61          211          147         >19.8
u_FC               274          483          206         >18.8
white              555         6332          369         >21.0
v                 5152         5352          197         >19.2
b                 4537         6171          393         >20.1
u                  274         5966          599         >19.6
w1                4126         5762          393         >20.1

The magnitudes in the table are not corrected for the Galactic 
extinction due to the reddening of E(B-V) = 0.02 in the direction of the 
burst (Schlegel et al. 1998).