TITLE:   GCN CIRCULAR
NUMBER:  17233
SUBJECT: GRB 141225A: UVOT detection
DATE:    14/12/26 02:16:13 GMT
FROM:    Paul Kuin at MSSL  <npkuin@gmail.com>

N.P.M. Kuin (MSSL/UCL) and P. D'Avanzo (INAF-OAB) report on behalf of the
Swift Team

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 427 seconds after the BAT trigger. There is a candidate afterglow
in
the rapidly available 2.7'x2.7' sub-image at
RA(J2000) =    09:15:06.92 = 138.77885
DEC(J2000) = +33:47:30.9 = 33.79191
with a 90%-confidence error radius of about 0.66 arc sec. This position is
2.3
arc sec. from the center of the XRT error circle. The estimated magnitude is
18.66 with a 1-sigma error of about 0.08.
A second exposure of 150 seconds in the White filter starting 858 seconds
after
the BAT trigger has an estimated magnitude of 19.61 with a 1-sigma error of
about 0.16, showing a clear decay. No correction has been made for the
expected extinction corresponding to E(B-V) of 0.02.