TITLE:   GCN CIRCULAR
NUMBER:  20232
SUBJECT: GRB 161202A: Swift/UVOT Upper Limits
DATE:    16/12/03 19:45:55 GMT
FROM:    Mike Siegel at PSU/Swift MOC  <siegel@swift.psu.edu>

M. H. Siegel (PSU) and B. Sbarufatti (INAF-OAB/PSU)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 161202A
83 s after the BAT trigger (Sbarufatti et al., GCN Circ. 20227).
No optical afterglow consistent with the XRT position
(Evans et al. GCN Circ. 20228)
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            83          232          147         >21.2
white               83         4066          344         >21.5
v                 4277         4477          197         >19.4
b                 3661        11907          862         >20.8
u                  295        10303         1027         >20.5
w1                4688         6144          217         >19.6
w2                4071         4271          197         >19.6

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.09 in the direction of the burst
(Schlegel et al. 1998).