NOTE: uvot_fluxes_wget.pl vrs. 2018-11-07 fem at 200821d16h18m45s946074usUT
NOTE: Source region spec. is: 353.570 -48.277 3"
NOTE: Used archived BAT position of 353.57000 -48.27700
NOTE: position reference is GCN_Position_Notice

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

GRB 200821: Swift/UVOT Upper Limits

K. K. Simpson (PSU) and ***BA*** (***BA INSTITUTION***)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 200821
152 s after the BAT trigger (***Author*** et al., GCN Circ. ????).
No optical afterglow consistent with the BAT position
*** POSITION REFERENCE is GCN_Position_Notice ***
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           152          302          147         >20.7
u_FC               310          560          246         >20.1
white              152         1362          373         >21.2
v                  641         1412           97         >18.9
b                  566         1338           78         >19.8
u                  310         1313          304         >20.2
w1                 690         1456           72         >19.2
m2                1071         1090           19         >18.6
w2                 789         1042           39         >19.0

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.01 in the direction of the burst
(Schlegel et al. 1998).