GCN Circular 19756

B. G. Balzer (PSU) and V. D'Elia (ASDC)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 160801A
90 s after the BAT trigger (D'Elia et al., GCN Circ. 19744
Not found
 
 
).
No optical afterglow consistent with the XRT position
(Goad et al. GCN Circ. 19746
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) exposure and the subsequent summed exposures:

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

white_FC            90          240          147         >20.50
u_FC               302          552          245         >19.91
white              581         1896          283         >20.94
v                  631         1945          155         >18.91
b                  557         1871          136         >19.90
u                  704         1846          116         >19.48
w1                1455         1474           19         >17.77

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).