NOTE: uvot_fluxes_wget.pl vrs. 2024-08-27 fem at 241218d04h09m55s569206usUT
NOTE: Source region spec. is: 185.68167 29.97319 4"
NOTE: Used archived XRT position of 185.68167  29.97319  4.00
NOTE: position reference is GCN_Circulars-38604

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

GRB 241218A: Swift/UVOT Upper Limits

***UBS*** (***INSTITUTION***) and M. Williams (PSU)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 241218A
152 s after the BAT trigger (Williams et al., GCN Circ. 38601).
No optical afterglow consistent with the XRT position
*** POSITION REFERENCE is GCN_Circulars-38604 ***
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           152          301          147         >20.7
u_FC               310          559          246         >19.8
white              152         1014          334         >21.0
v                  640         1411           97         >18.5
b                  565         1337           78         >18.7
u                  310         1312          304         >19.8
w1                 689          709           19         >21.1

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.024 in the direction of the burst
(Schlegel et al. 1998).