GCN Circular 5682
Subject
GRB 060930: near-IR afterglow candidate
Date
2006-10-02T10:49:55Z (18 years ago)
From
Alberto Castro-Tirado at Inst.de Astro. de Andalucia <ajct@iaa.es>
A. de Ugarte Postigo, M. Jelinek, A.J. Castro-Tirado,
J.Gorosabel (IAA-CSIC Granada), N. Pinilla-Alonso (TNG La Palma)
J. de Le��n Cruz (IAC Tenerife), J. Licandro (ING-IAC)
on behalf of a larger collaboration report:
We have observed the field of the GRB 060930 detected by INTEGRAL
(Gotz et al., GCN 5665) with the 3.5m Telescopio Nazionale Galileo
(+NICS) at La Palma in the JHK bands on 30 Sep 2006 (from 20:30 to
20:51 UT) and revisited the field in H band on 1 Oct 2006 (from
20:37 to 20:51 UT; i.e. 11.5 hr and 35.5 hr respectively after the
onset of the gamma-ray event).
The NICS frames cover the central 80% of the INTEGRAL/IBIS error
box (2.5' radius). We detect a variable, stationary object at the
following coordinates (J2000):
RA = 20:18:11.51, Dec = -23:37:19.6
with an astrometric error of 0.5".
In the first epoch the source is detected in all 3 bands and has
an H band magnitude of ~18.2. In the second H band epoch it has
faded by about 1 magnitude. This would imply a decay index of
alpha -0.9 +/- 0.2 .
For this object we obtain (Js-K)=1.10+/-0.22, consistent with the
near-IR colour expected for a GRB afterglow (Gorosabel et al. 2002,
A&A, 384, 11).
A finding chart is available at:
http://www.iaa.es/~deugarte/GRBs/060930/grb060930.gif
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