NOTE: uvot_fluxes_wget.pl vrs. 2020-11-03a fem at 210503d03h48m41s251418usUT
NOTE: Source region spec. is: 270.7590 -29.8302 4"
NOTE: Used archived XRT position of 270.75900 -29.83020  4.00
NOTE: position reference is GCN_Notice

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

GRB 210502: Swift/UVOT Upper Limits

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

The Swift/UVOT began settled observations of the field of GRB 210502
424 s after the BAT trigger (***Author*** et al., GCN Circ. ????).
No optical afterglow consistent with the XRT position
*** POSITION REFERENCE is GCN_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

v                  424         1412           62         >17.0
b                  688         1337           39         >18.5
u                  663         1486           97         >18.6
w1                 638         1462           97         >18.5
m2                 613         5439          159         >19.3
w2                 737         5167          274         >19.4

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.511 in the direction of the burst
(Schlegel et al. 1998).