GCN Circular 11963
Subject
GRB 110422A: TNG optical observations
Event
Date
2011-04-23T00:25:49Z (15 years ago)
From
Andrea Melandri at Liverpool John Moores U <axm@astro.livjm.ac.uk>
A. Melandri, P. D'avanzo, D. Fugazza (INAF-OAB) and E. Palazzi (INAF-IASFBo)
on behalf of a larger collaboration report:
We observed the field of GRB 110422A (Mangano et al. GCN 11957) with the 3.6m
TNG equipped with the Dolores camera. Few sets of unfiltered images were acquired
starting on Apr 22.89 UT (i.e. ~5.7 hours after the burst event).
The optical afterglow (Elunko et al. GCN 11958; Gres et al. GCN 11960; Xu et al.
GCN 11961, Moskvitin GCN 11962) is clearly detected in all our frames. The observed
magnitudes (calibrated with respect to the same star used in GCN 11961) are
Dt_start t_exp R_mag err
[hr] [s]
---------------------------------------------
5.777 60.0 20.17 0.03
5.934 60.0 20.24 0.05
5.998 60.0 20.03 0.05
8.052 60.0 20.24 0.04
Our observations, coupled with previous observations reported on GCNs imply a
power-law decay index for the optical afterglow of ~0.55.
Further observations are ongoing.
We thank the TNG staff for their support, in particular Massimo Cecconi
and Giovanni Mainella.
[GCN OPS NOTE(23apr11): Per author's request, the last sentence was added.]