GCN Circular 6590
Subject
GRB 070628: NIR detection of afterglow
Date
2007-06-29T19:54:12Z (17 years ago)
From
Jochen Greiner at MPI <jcg@mpe.mpg.de>
N. Primak, G. Szokoly, J. Greiner, C. Clemens, T. Kruehler, A. Kuepcue-Yoldas,
A. Yoldas (all MPE Garching), S. Klose, A. Rossi (Tautenburg Observatory),
and F. Carrier (Instituut voor Sterrenkunde Leuven, Belgium) report:
We observed the field of GRB 070628 (Swift trigger 283320; Holland et al.,
GCN 6584) with GROND at the 2.2m Max-Planck Institute telescope at the
ESO La Silla observatory in Chile. The observations started at 22:21:57,
about 7.7 hrs after the GRB and just after sunset, and lasted 10 min.
We observed simultaneously in the g,r,i,z,J,H,K bands. The UVOT afterglow
(Cronwall & Holland, GCN 6585) is clearly detected at H=16.2+-0.3 and
K=16.3+-0.2 mag. The NIR magnitudes are calibrated against 2MASS.
Nothing is visible in the J band (limiting magnitude 16.0), and all
optical frames are saturated due to twilight.
We note that the afterglow was atypically bright for the given time after
the burst, suggesting a slow fading. We encourage near-IR spectroscopy to
determine the redshift.