GCN Circular 10927
Subject
GRB 100526A: Gemini/NIRI afterglow confirmation and host galaxy
Date
2010-07-02T22:51:48Z (14 years ago)
From
Daniel Perley at U.C. Berkeley <dperley@astro.berkeley.edu>
D. A. Perley, J. S. Bloom, and S. B. Cenko (UC Berkeley) report:
We re-observed the field of GRB 100526A (Vetere et al., GCN 10797) with
NIRI on Gemini-North between 08:30 and 09:00 UT on 2010-06-24 UT. We
acquired 27 images of 60 seconds each in K-band.
Comparison to our previous K-band imaging of this field (Perley et al.,
GCN 10806) shows the infrared counterpart to have faded significantly.
A source is still detected at high significance at the afterglow
position. Using the same 2MASS reference star as for our previous
epoch, we measure a magnitude of:
K = 21.2 +/- 0.2 (t_mid = 27.7 days)
This corresponds to a decay index (t^-alpha) of only alpha~0.5 from our
previous epoch, which is much slower than expected for a late-time
afterglow, and suggests that the current epoch is likely host-galaxy
dominated.
A comparison image is posted to:
http://lyra.berkeley.edu/~dperley/100526a/100526a_niri.png
