GCN Circular 36517

S. P. R. Shilling (Lancaster U.), S. R. Oates (Lancaster U.), N. P. Kuin (UCL-MSSL),
A. A. Breeveld (UCL-MSSL) and T. M. Parsotan (GSFC) report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 240516A
150 s after the BAT trigger (Parsotan et al., GCN Circ. 36493
Not found
 
 
).
No optical afterglow consistent with the XRT position
(Parsotan et al., GCN Circ. 36493
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 initial exposures are:

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

white_FC          151          153            2          >17.8
white             150          1689           90         >19.9
v                 5228         5427           197        >18.9
m2                5432         5632           197        >18.9
w1                5638         5838           197        >19.1
u                 5843         5948           104        >19.1

        
We note that the first orbit of data only contained observations in the
white filter. The other filters are from a later orbit of data.

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 2.390 in the direction of the burst
(Schlegel et al. 1998).