TITLE:   GCN CIRCULAR
NUMBER:  7579
SUBJECT: Swift/UVOT observations of GRB080409
DATE:    08/04/09 13:01:18 GMT
FROM:    Patricia Schady at MSSL/Swift  <ps@mssl.ucl.ac.uk>

Swift/UVOT began settled observations of the field of GRB 080409 starting 
88s after the BAT trigger (Holland et al., GCN Circ 7573). We do not 
detect an optical/uv afterglow at the enhanced XRT position (Evans et al., 
GCN Circ. 7575) in the initial finding chart observations or subsequent 
summed images down to the following 3 sigma upper limits:

Filter  T_start T_stop  Exp.    Mag UL (3sig)
 	(s)	(s)	(s)
white   88      187     93      > 20.22
white   682     7079    494     > 21.16
v       188     587     393     > 19.45
v       721     12243   1099    > 20.03
b       667     676     412     > 20.42
u       642     661     432     > 20.13
uvw1    618     637     430     > 19.86
uvm2    593     12940   1070    > 20.23
uvw2    697     11330   1082    > 20.46

The above magnitudes are not corrected for the large Galactic extinction 
in the line of sight to GRB 080409, corresponding to a reddening of 
E(B-V)=0.78 mag (Schlegel et al., 1998, ApJS, 500, 525). The photometry is 
on the UVOT flight system described in Poole et al. (2008, MNRAS, 383, 
627).