[vsnet-grb-info 6845] GRB 081029: GROND Detection of the Optical/NIR Afterglow

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  8437
SUBJECT: GRB 081029: GROND Detection of the Optical/NIR Afterglow
DATE:    08/10/29 02:49:45 GMT
FROM:    Jochen Greiner at MPI  <jcg at mpe.mpg.de>

C. Clemens, S. Loew and J. Greiner (all MPE Garching) report on behalf of the 
GROND team:

We observed the field of GRB 081029 (Swift trigger 332931; Sakamoto et al., 
GCN #8435) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, 
PASP 120, 405) mounted at the 2.2 m ESO/MPI telescope at La Silla Observatory 
(Chile).

Observations started at 01:52 UT on October 29th, 2008, 8.2 min after the 
GRB trigger, and are continuing. They were performed at an average seeing 
of 1.0" and at an average airmass of 1.3.

We found a bright point source at the position reported by Rykoff et al. 
(GCN #8436), at magnitude r'=17.8 during the first 4 min integration,
calibrated with the GROND zeropoint.

The object is seen in g' band, implying a redshift smaller than 3.5.