TITLE:   GCN CIRCULAR
NUMBER:  15294
SUBJECT: GRB 131002A: Swift/UVOT Detection
DATE:    13/10/03 11:42:38 GMT
FROM:    Alice Breeveld at MSSL-UCL  <a.breeveld@ucl.ac.uk>

A. A. Breeveld (UCL-MSSL) and B. N. Barlow (High Point University) 
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 131002A 77 
s after the BAT trigger (Barlow et al., GCN Circ. 15283). A fading 
source consistent with the optical position (Guidorzi GCN Circ. 15282) 
is detected in the initial UVOT exposures.

Preliminary detections and 3-sigma upper limits using the UVOT 
photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for 
the early exposures are:

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

white               77          227          147         17.94 ± 0.06
white              870         1020          147         19.40 ± 0.11
v                  620         1071           59         18.89 ± 0.36
b                  546          739           39         19.41 ± 0.31
u                  290         7169          736        >21.1
w1                 669         6964          510        >20.7
m2                 645        13293          939        >21.1
w2                 770        11860         1199        >21.5

The magnitudes in the table are not corrected for the Galactic 
extinction due to the reddening of E(B-V) = 0.08 in the direction of the 
burst (Schlegel et al. 1998).