GCN Circular 36870

N. P. M. Kuin (UCL-MSSL) and C. Salvaggio (INAF-OAB)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 240712A
141 s after the BAT trigger (Salvaggio et al., GCN Circ. 36851
Not found
 
 
).
No optical afterglow consistent with the XRT position in GCN Circ
36851
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           141          290          147         >20.2
u_FC               299          549          246         >19.9
white              141         1550          392         >21.0
v                  629         5288          179         >19.0
b                  555         1525           97         >20.0
u                  299         1500          324         >20.3
w1                 678         1476           97         >19.2
m2                 653         1451           97         >18.7
w2                 604         5200          313         >19.8

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.996 in the direction of the burst
(Schlegel et al. 1998).