[vsnet-grb-info 11652] GRB 120311B: Faulkes Telescope North observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  13045
SUBJECT: GRB 120311B: Faulkes Telescope North observations
DATE:    12/03/12 08:58:55 GMT
FROM:    Cristiano Guidorzi at Ferrara U,Italy  <guidorzi at fe.infn.it>

C. Guidorzi (U. Ferrara), A. Melandri (INAF-OAB), F. Virgili (LJMU),
J. Japeli (U. Ljubljana)  on behalf of a larger collaboration report:

"The 2-m Faulkes Telescope North robotically followed up GRB 120311B
(Swift trigger 517489, Marshall et al., GCN Circ 13038) 200 sec after
the GRB trigger time. Within the enhanced XRT error circle (Osborne et
al., GCN Circ. 13042) we do not detect any object in R and i' filters
down to the following limits:

Mid time from       Exposure        Filter       Magnitude
GRB (hr)            (s)
----------------------------------------------------------
0.29                240             R > 20.5
0.39                220             i' > 20.3
----------------------------------------------------------

Values are calibrated against nearby USNOB-1 field stars.