TITLE:   GCN CIRCULAR
NUMBER:  23080
SUBJECT: GRB 180805B: Swift/UVOT Upper Limits
DATE:    18/08/05 22:12:32 GMT
FROM:    Paul Kuin at MSSL  <npkuin@gmail.com>

N. P. M. Kuin (UCL-MSSL) and P. D'Avanzo (INAF-OAB)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of
GRB 180805B  85 s after the BAT trigger (D'Avanzo et al.,
GCN Circ. 23076).  No optical afterglow consistent with the
XRT position (Evans et al. GCN Circ. 23077) 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            85          235          147         >20.8
u_FC               297          546          246         >20.2
white               85         1544          392         >21.3
v                  626         1421           78         >18.6
b                  552         1519           97         >20.0
u                  297          546          246         >20.2
w1                 675         1470           97         >18.8
m2                1078         1097           19         >17.8
w2                 774         1569           78         >19.0

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).