[vsnet-grb-info 9830] GRB100925A UVOT afterglow

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  11298
SUBJECT: GRB100925A UVOT afterglow
DATE:    10/09/25 12:23:06 GMT
FROM:    Phil Evans at U of Leicester  <pae9 at star.le.ac.uk>

F. E. Marshall (NASA/GSFC) reports on behalf of the Swift team:

In response to GRB100925 (Swift/BAT trigger 434928), UVOT took a finding chart 
exposure of 150 seconds with the White filter starting 1882 seconds after the 
BAT trigger. There is a candidate afterglow in the rapidly available 2.7'x2.7' 
sub-image at
RA(J2000) =   16:59:01.68 = 254.75702
DEC(J2000) = -15:15:28.4 = -15.25789
with a 90%-confidence error radius of about 0.61 arc sec.
This position is 11" from the center of the XRT error circle (Mangano et al. GCN 
Circ. 11296). The estimated magnitude is 16.83 with a 1-sigma error of about 
0.14. No correction has been made for the expected extinction corresponding to 
E(B-V) of 0.61.