GCN Circular 11859
Subject
GRB 110402A: NOT afterglow confirmation
Event
Date
2011-04-02T02:51:06Z (15 years ago)
From
Giorgos Leloudas at Dark Cosmology Centre <giorgos@dark-cosmology.dk>
G. Leloudas (DARK/NBI), D. Xu (WIS), P. Jakobsson (U. Iceland), M.
Bayliss (U. Chicago/KICP), report on behalf of a larger collaboration:
We observed the field of GRB 110402A (Ukwatta et al., GCN 11857) with
the Nordic Optical Telescope (La Palma, Spain) equipped with MOSCA.
Observations started at 01:26:09.0 UT (73.9 mins after the GRB).
We obtained 3x300 s in the R filter.
We detect a transient within the XRT error circle consistent with the
position reported in Mundell et al. (GCN 11858).
Between the 1st and 3rd exposures, the optical transient shows
marginal decay from 21.10 +- 0.02 to 21.17 +- 0.04 mag, calibrated
with respect to the USNO
B1 star 1512-0199231 (R1= 16.71 mag).
Since the object has also faded by 0.3 mag with respect to GCN 11858,
we suggest that this is the afterglow of GRB 110402A.