NOTE: uvot_fluxes_wget.pl vrs. 2018-11-07 fem at 200529d10h12m10s848324usUT
NOTE: Source region spec. is: 176.63746 58.19258 4"
NOTE: Used archived XRT position of 176.63746  58.19258  4.00
NOTE: position reference is GCN_Circulars-27836

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

GRB 200528A: Swift/UVOT Upper Limits

F. E. Marshall (NASA/GSFC) and Ambrosi (INAF-IASFPA)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 200528A
80 s after the BAT trigger (Ambrosi et al., GCN Circ. 27832).
No optical afterglow consistent with the XRT position
(Evans et al. GCN Circ. 27836)
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            80          230          147         >21.1
white               80          230          147         >21.1
u                  292          304           12         >18.7

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).