GCN Circular 7881

E. A. Hoversten (PSU) and S. T. Holland (CRESST/USRA/GSFC) on behalf
of the Swift/UVOT team.

The Swift Ultra-Violet/Optical Telescope (UVOT) began settled
observations of the INTEGRAL-detected GRB 080613A (Gotz, et al., GCN
Circ. 7871
Not found
 
 
) 6.7 hours after the trigger.  No afterglow is detected at the
position of the R-band detection by the Faulkes Telescope North
(Guidorzi, et al., GCN Circ. 7872
Not found
 
 
).  The 22.2 magnitude upper limit in
the white band suggests the R~19 object seen by Guidorzi, et al. 3.9
minutes after the trigger has faded and is indeed the afterglow.


Filter  T_start(s)  T_stop(s)  Exp(s)  Mag UL (3sig)

white     24725      25189      456     >22.2
v         25195      25638      436     >20.5
b         24257      24720      456     >21.5

The values quoted above are in the UVOT photometric system (Poole et al.
2008, MNRAS, 383, 627).  They are not corrected for the expected
Galactic extinction corresponding to a reddening of E(B-V)=0.023 mag in
the direction of the burst (Schlegel et al. 1998).