GCN Circular 5605
Subject
GRB 060923A: Gemini Second Epoch and Afterglow Confirmation
Date
2006-09-24T22:34:47Z (18 years ago)
From
Derek Fox at PSU <dfox@astro.psu.edu>
D.B. Fox (Penn State) reports on behalf of a larger collaboration:
"We have imaged the Swift XRT localization region for GRB060923A
(Stamatikos et al., GCN 5583) with Gemini-North + NIRI on a second
occasion. The candidate afterglow of Tanvir et al. (GCN 5587) and Fox
et al. (GCN 5597) is no longer detected, and we estimate its
brightness as:
K-band: Ks>21.5 mag at 05:05 UT, 24 Sep (mean epoch)
using the same photometric calibration as for the previous night (GCN
5597). Fading of the candidate by >~1 mag between our two epochs is
separately confirmed in an image subtraction analysis.
This confirms the afterglow nature of the source, and thus the highly
reddened, high-redshift and/or highly-extinguished nature of the
afterglow of GRB 060923A."