GCN Circular 35475

A. Belles (PSU) and J. D. Gropp (PSU)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 240102A
113 s after the BAT trigger (Gropp et al., GCN Circ. 35461
Not found
 
 
).
No optical afterglow consistent with the XRT position
(Goad et al., GCN Circ. 35471
Not found
 
 
) 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           135          285          147         >20.7
u_FC               294          544          246         >19.9
white              135         1196          353         >21.1
v                  113         1246           90         >18.8
b                  550         1172           58         >19.5
u                  294         1314          299         >20.0
w1                 676         1295           78         >19.0
m2                 823         1270           58         >18.7
w2                 600         1221           78         >19.3

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.176 in the direction of the burst
(Schlegel et al. 1998).