GCN Circular 7611

S. R. Oates and M. Stamatikos report on behalf of the Swift/UVOT team.

The Swift/UVOT began settled observations of the field of GRB 080413B 135s
after the BAT trigger (Stamatikos et al., GCN 7598
Not found
 
 
). We detect the 
afterglow
in the 7 UVOT filters at the position:

RA(J2000.0)  =  21:44:34.65
DEC(J2000.0) = -19:58:52.40

with an estimated uncertainty of 0.5 arcsec (radius, 90% confidence). 
This position is
consistent with the refined XRT position and the GROND optical position 
(Kruehler et al., GCN 7599
Not found
 
 
).

The magnitudes are reported below:

Filter    T_Mid(s)   Expo(s)               Magnitude
-------------------------------------------------------
White       184       98                 16.67 � 0.02
White       740       10                 17.67 � 0.15
v           440       393                17.64 � 0.10
v           1183      393                18.64 � 0.22
b           727       10                 18.82 � 0.71
u           796       19                 17.67 � 0.27
w1          682       19                 17.42 � 0.27
m2          810       19                 18.07 � 0.47
w2          762       19                 17.92 � 0.36
-------------------------------------------------------

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).