NOTE: uvot_fluxes_wget.pl vrs. 2020-11-03a fem at 210919d18h38m53s723424usUT
NOTE: Source region spec. is: 80.25450 1.31153 4"
NOTE: Used archived XRT position of  80.25450   1.31153  4.00
NOTE: position reference is GCN_Circulars-30850

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

GRB 210919A: Swift/UVOT Upper Limits

M. H. Siegel (PSU) and A. Tohuvavohu (U. Toronto)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 210919A
100 s after the BAT trigger (Tohuvavohu et al., GCN Circ. 30846).
No optical afterglow consistent with the XRT position
(Goad et al. GCN Circ. 30850)
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           100          249          147         >20.7
u_FC               312          561          246         >19.9
white              100         1539          389         >21.4
v                  643         1589          114         >18.9
b                  568         1515           91         >19.3
u                  312         1490          324         >19.8
w1                 693         1466           78         >18.9
m2                 668         1441           58         >20.6
w2                 618         1565           58         >19.3

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.141 in the direction of the burst
(Schlegel et al. 1998).