TITLE:   GCN CIRCULAR
NUMBER:  6611
SUBJECT: Swift/UVOT Observations of GRB070707
DATE:    07/07/08 18:56:30 GMT
FROM:    Patricia Schady at MSSL/Swift  <ps@mssl.ucl.ac.uk>

P. Schady (MSSL-UCL) and A. Parsons (GSFC) report on the behalf of the 
Swift UVOT team:

The Swift/UVOT observed the field of INTEGRAL burst, GRB070707 starting 8.8hrs 
after the INTEGRAL trigger (Beckmann et al. 2007, GCN Circ. 6606). We do not 
find any new source in any of the UVOT observations inside the refined INTEGRAL 
error circle (Gotz et al. 2007, GCN Circ. 6607) or XRT error circle (Beardmore 
et al. 2007, GCN 6610)

The 3-sigma upper limits for detecting a source inside the refined XRT
error circle in the initial data products are:

Filter    T_mid(s) Exp(s) Mag (3-sigma upper limit)
-------------------------------------------------------
V         53885    543      19.7
B         31910    324      20.6
U         47905    97       19.5
UVW1      47149    964      20.3
UVM2      39328    1190     20.5
UVW2      53182    1800     20.5
-----------------------------------------------------------------

where T_mid is the weighted mid time of the coadded exposure. The values
quoted above are not corrected for the expected Galactic extinction
corresponding to a reddening of E_{B-V} = 0.08 mag in the direction of the
burst (Schlegel et al. 1998).