NOTE: uvot_fluxes_wget.pl vrs. 2020-11-03a fem at 210930d09h10m32s363719usUT
NOTE: Source region spec. is: 197.40183 48.62853 4"
NOTE: Used archived XRT position of 197.40183  48.62853  4.00
NOTE: position reference is GCN_Circulars-30897

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

GRB 210930A: Swift/UVOT Upper Limits

A. Belles (PSU) and V. D'Elia (SSDC & INAF-OAR)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 210930A
144 s after the BAT trigger (D'Elia et al., GCN Circ. 30897).
No optical afterglow consistent with the XRT position
(D'Elia et al. GCN Circ. 30897)
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           144          293          147         >19.9
u_FC               302          551          246         >19.6
white              144         1722          411         >20.6
v                  631         1773          136         >18.7
b                  559         1873          134         >19.6
u                  302         1848          363         >19.7
w1                 681         1824          136         >19.5
m2                 655         1450           39         >18.7
w2                 607         1747          117         >20.4

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.010 in the direction of the burst
(Schlegel et al. 1998).