[vsnet-grb-info 7979] GRB 090618 Faulkes Telescope North observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  9520
SUBJECT: GRB 090618 Faulkes Telescope North observations
DATE:    09/06/18 13:32:21 GMT
FROM:    David Bersier at Liverpool John Moores U  <dfb at astro.livjm.ac.uk>

A.Melandri (Liverpool JMU), C. Guidorzi (U. Ferrara), D.  Bersier,
Z. Cano, I.A. Steele, C.G. Mundell (Liverpool JMU), P. O'Brien,
N.  Tanvir (U. Leicester) on behalf of a larger collaboration report:


We have been monitoring the field of GRB090618 (Swift trigger 355083),
with the Faulkes Telescope North (Hawaii), starting ~80 minutes after
the trigger time (Schady et al. GCN 9512).

Observations were performed with BVRi filters. The optical afterglow
reported by Cenko (GCN 9513), Perley (GCN 9514) and Rujopakarn et al.
(GCN  9515) is clearly visible and detected in all filters.
We find a magnitude of R=17.01 ± 0.03 (at 2.5 hrs after the burst)
and R=17.25 ± 0.05 (at 3.1 hrs). We confirm the decay of alpha~0.7
reported by Li et al. (GCN 9517).

Observations are continuing.