TITLE:   GCN CIRCULAR
NUMBER:  8161
SUBJECT: GRB080828: Swift/UVOT Upper Limits
DATE:    08/08/29 17:08:41 GMT
FROM:    Paul Ward at MSSL  <paw@mssl.ucl.ac.uk>

P. Ward (MSSL-UCL) and W. Baumgartner (GSFC/UMBC) report on behalf of the 
Swift/UVOT team:

The Swift/UVOT observed the field of GRB 080828 starting 39.15ks after the 
SuperAGILE detection (Del Monte et al., GCN Circ. 8151).  We do not detect 
any afterglow at the Swift XRT position reported by Beardmore et al.
(GCN Circ. 8157) in any of the following UVOT filters down to the given 3
sigma upper limits.

Filter T_start(s) T_stop Exp(s)  MagLimit

White  46201      46561  355.8   > 21.40
u      44376      51948  1798.8  > 20.65
b      45289      52309  1250.3  > 21.33
w1     40064      51035  1615.6  > 21.05
m2     39156      40055  899.8   > 20.50

The photometry is on the UVOT photometric system described in Poole et al. 
(2008, MNRAS, 383,627). The above magnitudes are not corrected for the 
Galactic extinction corresponding to a reddening of E(B-V) ~ 0.81 mag 
(Schlegel et al., 1998).