TITLE:   GCN CIRCULAR
NUMBER:  37056
SUBJECT: GRB 240805A: Swift/UVOT Upper Limits
DATE:    24/08/06 01:34:23 GMT
FROM:    Mike Siegel at PSU/Swift MOC <mhs18@psu.edu>

M. H. Siegel (PSU) and S. Dichiara (PSU)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 240805A
105 s after the BAT trigger (Dichiara et al., GCN Circ. 37032).
No optical afterglow consistent with the XRT position
(Osborne, GCN Circ. 37045) 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              105         4086          269         >20.4
v                 4297         4497          197         >18.7
b                 3681         5128          205         >19.5
u                 3476         5113          393         >19.5
w1                4708         4908          197         >19.1
m2                4502         4701          197         >19.1
w2                4092         4292          197         >19.1

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.191 in the direction of the burst
(Schlegel et al. 1998).