GCN Circular 7834
Subject
GRB 080605: GROND detection of the optical afterglow candidate
Date
2008-06-06T04:30:38Z (17 years ago)
From
Christian Clemens at MPE <cclemens@mpe.mpg.de>
C. Clemens, T. Kruehler, J. Greiner, A. Kupcu Yoldas, A. Yoldas (all MPE
Garching) and G. Szokoly (Eoetvoes Univ., Budapest and MPE Garching) report
on behalf of the GROND team:
We observed the field of GRB 080605 (Swift trigger 313299; Sbarufatti et al.,
GCN #7828) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008,
PASP 120, 405) mounted at the 2.2m ESO/MPI telescope at La Silla Observatory
(Chile).
Observations started at 01:10:59 UT on June 6th, 2008, 83 mins after the GRB
trigger, and are continuing.
We found a single and relatively bright point source within the 1.0''
Swift-UVOT error circle reported by Holland et al. (GCN #7830) at
RA (J2000.0) = 17h 28m 30.05s
DEC (J2000.0) = +04d 00' 56.2"
with a typical uncertainty of 0.8", which is consistent with the sources
reported by Kann et al. (GCN #7829) and Gomboc et al. (GCN #7831).
Based on 460 s and 1500 s of effective exposures taken 1.65 hrs and 2.78 hrs
after the trigger, we estimate preliminary magnitudes of
r' = 20.3 and i' = 19.4, as well as
r' = 20.7 and i' = 19.9
with typical errors of +/- 0.1. (Given magnitudes are calibrated against
USNO-B1 field stars and might be affected by the bright, nearby star.)
This indicates a clear fading of the source, which we therefore suggest to be
the optical afterglow of GRB 080605.