GCN Circular 36978

Paul Kuin (MSSL/UCL), R. Caputo and S. B. Cenko (GSFC)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 240730A
133 s after the BAT trigger (Cenko et al., GCN Circ. 36976
Not found
 
 
).
No optical afterglow consistent with the XRT position in Evans et al.,
GCN Circ. 36977
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           133          283          147         >19.1
u_FC               291          541          246         >19.2
white              133         1026          295         >19.1
u                  291          541          246         >19.2

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 1.146 in the direction of the burst
(Schlegel et al. 1998).