GCN Circular 23407

GRB 181103A: Swift/UVOT Detection

S. J. LaPorte (PSU) and A. Tohuvavohu (PSU)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 181103A
92 s after the BAT trigger (Tohuvavohu et al., GCN Circ. 23402
Not found
 
 
).
A fading source is detected in the initial UVOT exposures at a position
consistent with the XRT position (Evans et al., GCN Circ. 23403
Not found
 
 
).

Preliminary detections and 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

b              534           898            58          >19.08
uvm2           632          1126            57          >18.19
u              279           874           530           19.58+-0.25 
v              608          1103            58          >18.21
uvw1           657           849            38          >18.16
uvw2           584          1079            58          >18.36
white_FC          121           271           294           20.47+-0.29 
white       559          6763           579          >21.12  

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.03 in the direction of the burst
(Schlegel et al. 1998).