NOTE: uvot_fluxes_wget.pl vrs. 2023-03-23 fem at 230817d03h44m42s448169usUT
NOTE: Source region spec. is: 328.44542 37.85442 3"
NOTE: Used archived opt source position of 328.44542  37.85442  3.00
NOTE: position reference is GCN_Circ-34453

=========== Draft Upper Limit Circular ========

GRB 230816A: Swift/UVOT Upper Limits

***UBS*** (***INSTITUTION***) and M. H. Siegel (PSU)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 230816A
94 s after the BAT trigger (Siegel et al., GCN Circ. 34450).
No optical afterglow consistent with the optical position
*** POSITION REFERENCE is GCN_Circ-34453 ***
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            94          243          147         >20.9
u_FC               306          556          246         >20.0
white               94         1185          353         >21.3
v                  636         1236           78         >18.7
b                  562         1160           58         >19.9
u                  306         1306          300         >20.1
w1                 685         1285           58         >19.5
w2                 611         1211           58         >19.6

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.312 in the direction of the burst
(Schlegel et al. 1998).