NOTE: uvot_fluxes_wget.pl vrs. 2020-11-03a fem at 210603d15h59m26s980780usUT
NOTE: Source region spec. is: 238.819 -54.046 3"
NOTE: Used archived BAT position of 238.81900 -54.04600
NOTE: position reference is GCN_Position_Notice

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

GRB 210603: Swift/UVOT Upper Limits

***UBS*** (***INSTITUTION***) and ***BA*** (***BA INSTITUTION***)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 210603
100 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 initial exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

white              100         4818          404         >20.9
v                 5029         5228          197         >18.8
b                 4415         4613          195         >19.8
u                 4215         5722          270         >19.8
w1                5439         5638          197         >19.3
m2                5234         5433          197         >19.4
w2                4824         5024          197         >19.5

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 18.831 in the direction of the burst
(Schlegel et al. 1998).