GCN Circular 38717

N. P. M. Kuin (UCL-MSSL) and A. D'Ai (INAF-IASFPA SSDC)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began observations of the field of GRB 241229B
6.5 hours after the BAT trigger due to an observing constraint
(D'Elia et al., GCN Circ. 38699
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 ).  No optical afterglow
consistent with the XRT position (Evans, GCN Circ. no 38708)
was detected with UVOT.

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

b                23500        39885         1686         >21.5
uvw1             27820        45505         1800         >21.0
u                28727        45738          404         >20.3
uvw2             33481        51179         1800         >21.2
v                34386        51381          376         >20.0
white            39890        40021          132         >20.9
b                55868        56383          254         >20.7

The magnitudes in the table are not corrected for the
Galactic extinction due to the reddening of E(B-V) = 0.06
in the direction of the burst (Schlegel et al. 1998).