TITLE:   GCN CIRCULAR
NUMBER:  14641
SUBJECT: GRB 130513A: Swift/UVOT Upper Limits
DATE:    13/05/14 17:31:32 GMT
FROM:    Frank Marshall at GSFC  <femarsha@khamseen.gsfc.nasa.gov>

F. E. Marshall (NASA/GSFC) reports on behalf of the Swift team:

The Swift/UVOT began settled observations of the field of GRB 130513A
25261 s after the INTEGRAL trigger (Mereghetti et al., GCN Circ. 14630).
No optical afterglow consistent with the XRT position
(Evans and Marshall GCN Circ. 14635) 
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            25885        32269         1218         >21.9
v                26510        32924         1267         >20.6
u                25261        37138         1399         >21.6

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).