TITLE:   GCN CIRCULAR
NUMBER:  7607
SUBJECT: GRB080413A: Swift/UVOT observations
DATE:    08/04/13 17:49:17 GMT
FROM:    Samantha Oates at MSSL  <sro@mssl.ucl.ac.uk>

S. R. Oates and F. E. Marshall report on behalf of the Swift/UVOT team.

The Swift/UVOT observed the field of GRB 080413A starting at 77s after 
the BAT
trigger (Beardmore et al., GCN 7594). We detect the afterglow in 
white,v,b and
u filters at the position:

RA(J2000.0)  =   19:09:11.76
DEC(J2000.0) =  -27:40:40.27

with an estimated uncertainty of 0.5 arcsec (radius, 90% confidence). 
This position is
consistent with the enhanced XRT position and the position reported by 
ROSTE-III
(Rykoff et al., GCN 7593).

The magnitudes and 3 sigma upper limits are reported below:

Filter    T_Mid(s)   Expo(s)          Magnitude/3sigUL
-----------------------------------------------------
White     126          98               15.37 +/- 0.01
White     5478         197              19.74 +/- 0.17
v         268          169              15.08 +/- 0.03
v         5888         197              19.16 +/- 0.51
b         5273         197              19.33 +/- 0.21
u         5068         197              19.05 +/- 0.22
w1        4863         197              >19.55
m2        4658         197              >19.48
w2        5684         197              >19.57
-----------------------------------------------------

The above magnitudes are not corrected for the Galactic extinction 
corresponding to a
reddening of E_{B-V} = 0.16 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).