NOTE: uvot_fluxes_wget.pl vrs. 2020-11-03a fem at 211222d01h23m55s395654usUT
NOTE: Source region spec. is: 78.8983 +0.9144 4"
NOTE: Used archived XRT position of  78.89830   0.91440  4.00
NOTE: position reference is GCN_Notice
WARNING: Did not recognize UBS name.

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

GRB 211221A: Swift/UVOT Upper Limits

PSU (***INSTITUTION***) and K. L. Page (U. Leicester)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 211221A
63 s after the BAT trigger (Page et al., GCN Circ. 31273).
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 first
finding chart (FC) exposure and subsequent exposures are:

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

white_FC            63          213          147         >20.7
u_FC               275          525          246         >20.1
white               63         1010          317         >21.1
v                  606          799           39         >18.6
b                  531          724           39         >19.4
u                  275          872          285         >20.0
w1                 655          848           39         >18.1
m2                 631          650           19         >17.8
w2                 582          774           39         >19.0

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.143 in the direction of the burst
(Schlegel et al. 1998).