NOTE: uvot_fluxes_wget.pl vrs. 2023-03-23 fem at 231231d00h18m47s623166usUT
NOTE: Source region spec. is: 245.21437 58.12394 4"
NOTE: Used archived XRT position of 245.21437  58.12394  4.00
NOTE: position reference is GCN_Circulars-35441
WARNING: t_start for light curve (304) and t_start from the exposure report (145) do not agree.
  Replace ??? in draft Circular with correct value.

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

GRB 231230A: Swift/UVOT Upper Limits

N. P. M. Kuin (UCL-MSSL) and M. J. Moss (GSFC)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 231230A
***???*** s after the BAT trigger (Moss et al., GCN Circ. 35436).
No optical afterglow consistent with the XRT position
*** POSITION REFERENCE is GCN_Circulars-35441 ***
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

u_FC               304          554          246         >19.7
white              586         1531          206         >20.2
v                 1042         1235           39         >18.2
b                  560         1681           58         >19.4
u                  304          554          246         >19.7
w1                 686         1632           78         >18.7
m2                5469         5594          123         >21.5
w2                 611         1731           39         >18.5

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.015 in the direction of the burst
(Schlegel et al. 1998).