TITLE: GCN CIRCULAR NUMBER: 7577 SUBJECT: UVOT/Swift Observations of GRB080408 DATE: 08/04/09 11:20:42 GMT FROM: Patricia Schady at MSSL/Swift P. Schady (MSSL-UCL) reports on behalf of the Swift-UVOT team: The Swift/UVOT performed a Target of Opportunity observation on the SuperAGILE GRB 080408 (Soffitta et al., GNCN Circ. 7571), starting ~7hrs after the trigger. Observations were made in the b, u and uvw1 filters. The optical afterglow is not detected in any of these filters at the XRT position (Page et al., GCN Circ 7576) down to the following 3 sigma upper limits: Filter Tstart Exp Mag UL (3sig) (hrs) (s) b 7.12 185 > 19.96 u 7.06 200 > 19.63 uvw1 6.95 399 > 19.97 The above magnitudes are not corrected for the Galactic extinction corresponding to a reddening of E(B-V)=0.04 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).