TITLE:   GCN CIRCULAR
NUMBER:  38717
SUBJECT: GRB241229B: UVOT upper limits
DATE:    24/12/29 23:57:41 GMT
FROM:    Paul Kuin at MSSL <npkuin@gmail.com>

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).  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).