GCN Circular 36193

S. P. R. Shilling (Lancaster U.), S. R. Oates (Lancaster U.), A. A. Breeveld (UCL-MSSL), M. De Pasquale (Univ. of Messina) and M. H. Siegel (PSU)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 240419A
113 s after the BAT trigger (Siegel et al., GCN Circ. 36169
Not found
 
 
).
No optical afterglow consistent with the enhanced XRT position (Goad et al., GCN Circ. 36174
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) exposures and subsequent exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

white_FC           113          263          147         >20.7
u_FC               271          521          246         >20.0
white              113         1025          334         >21.3
v                  602         1075           58         >18.6
b                  527          721           39         >19.3
u                  271          869          285         >20.1
w1                 652          845           39         >18.2
m2                 627         1099           58         >18.3
w2                 578         1050           58         >18.6

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.070 in the direction of the burst
(Schlegel et al. 1998).