[vsnet-grb-info 6334] UVOT observations of GRB080707

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  7953
SUBJECT: UVOT observations of GRB080707
DATE:    08/07/07 22:52:44 GMT
FROM:    Patricia Schady at MSSL/Swift  <ps at mssl.ucl.ac.uk>

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

The Swift/UVOT starting taking settled exposures of the field of GRB 
080707 80 s after the BAT trigger (Schady et al., GCN Circ. 7947). A faint 
source is detected in the early white and v-band observations at

     RA(J2000.0)  = 02:10:28.40 = 32.61833
     Dec(J2000.0) = +33:06:34.2 = 33.10950

with an of 1.1 arcseconds (90% confidence), consistent with the enhanced 
XRT error circle (Starling et al., GCN Circ. 7951) and the GROND position 
(Clemens et al., GCN 7948).

The early-time afterglow and 3-sigma upper limits the in co-added frames 
are as follows:

Filter T_start(s)  T_stop(s)  Exp(s)  Mag/3-sigma UL

white   80          5469        294.0    21.40+/-0.31 (3.4 sigma)
white   11355       12221       844.3    > 21.93
v       186         5880        590.1    19.97+/-0.31 (3.4 sigma)
b       3971        18004       1502.6   > 21.74
u       640         17362       1040.0   > 21.18
uvw1    616         16449       1101.7   > 21.41
uvm2    591         22234       1101.7   > 21.29
uvw2    5477        5676        196.6    > 20.22

The values quoted above are not corrected for the expected Galactic 
extinction corresponding to a reddening of E(B-V) = 0.10 mag in the 
direction of the burst (Schlegel et al. 1998).