GCN Circular 9495

P.A. Curran (UCL-MSSL) and F. Marshall (NASA/GSFC)
report on behalf of the Swift/UVOT team:


The Swift/UVOT began settled observations of the field of GRB 090607
75 s after the BAT trigger (Marshall et al., GCN Circ. 9491
Not found
 
 
). No optical 
afterglow consistent with the XRT position (Marshall et al., GCN Circ. 
9491
Not found
 
 
) is detected in the initial UVOT exposures. Preliminary 3-sigma 
upper limits using the UVOT photometric system (Poole et al. 2008, 
MNRAS, 383, 627) for the first finding chart (FC) exposure and 
subsequent exposures are:


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

uvw1           12715       13943       1209         >20.8
u              75          1233        1140         >21.2
v              11448       12707       1239         >20.4


The values quoted above are not corrected for the Galactic extinction 
due to the reddening of E(B-V) = 0.02 in the direction of the burst
(Schlegel et al. 1998).