GCN Circular 23303

GRB 181003A: Swift/UVOT Upper Limits

S. J. LaPorte (PSU) and A. P. Beardmore (U. Leicester)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 181003A
3095 s after the BAT trigger (Beardmore et al., GCN Circ. 23295
Not found
 
 
).
No optical afterglow consistent with the XRT position
(Evans et al. GCN Circ. 23296
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

b              5040         5240           196            >20.83  
uvm2           3452         3652           196            >19.46 
u              3862         3902            39            >19.19 
v              3427         3447           196            >19.79 
uvw1           3658         3857           196            >19.85
uvw2           5451         5597           144            >19.37 
white          3091         3240           294            >21.73  

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.01 in the direction of the burst
(Schlegel et al. 1998).