[vsnet-grb-info 12178] GRB 120803B: FTN possible afterglow candidate

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  13567
SUBJECT: GRB 120803B: FTN possible afterglow candidate
DATE:    12/08/03 12:40:19 GMT
FROM:    Cristiano Guidorzi at Ferrara U,Italy  <guidorzi at fe.infn.it>

C. Guidorzi (U. Ferrara), C.G. Mundell, D. Bersier (LJMU),
N.R. Tanvir (U. Leicester) report on behalf of a larger
collaboration:

The 2-m Faulkes Telescope North automatically began observing
GRB 120803B (Racusin et al. GCN Circ. 13566) on August 03 2012,
11:09:06 UT corresponding to 180 seconds post burst trigger
with BVRi' filters. Within the XRT error circle, in the i-band
filter we found the following uncatalogued possibly fading source,

R.A. = 20:56:56.46
Dec = +53:18:14.4   (J2000)

with an uncertainty of about 1".
The detection is marginal, with an estimated magnitude of
19.5 +/- 0.5 in the i band at a mean time of 13.2 minutes
(100 s exposure) calibrated against nearby USNOB-1 stars.
The source is no longer visible in the latest frames.
In the R band we see nothing down to 21.4 mag at 32.5 minutes
post burst. The faintness and colour of the source might
partially be explained by the relatively large foreground
extinction, E(B-V)=1.7.