TITLE:   GCN CIRCULAR
NUMBER:  14768
SUBJECT: GRB 130604A: Swift/UVOT Upper Limits
DATE:    13/06/05 10:15:08 GMT
FROM:    Alice Breeveld at MSSL-UCL  <a.breeveld@ucl.ac.uk>

A. A. Breeveld (MSSL-UCL) and A. Melandri (INAF-OAB) report on behalf of 
the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 130604A 
109 s after the BAT trigger (Melandri et al., GCN Circ. 14752). No 
optical afterglow consistent with the optical position (Perley, GCN 
Circ. 14753) 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 first finding 
chart (FC) exposure and subsequent exposures are:

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

white_FC           109          258          147         >20.4
white              109        17767         1345         >21.8
v                 5004        11999         1055         >20.3
b                 4388        16933         1278         >21.5
u                  267         5818          378         >20.0
w1                5414         5613          197         >20.0
m2                5208         5408          197         >19.7
w2                4798        11112         1082         >21.3

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).