Skip to main content
Testing. You are viewing the public testing version of GCN. For the production version, go to
New Announcement Feature, Code of Conduct, Circular Revisions. See news and announcements

GCN Circular 8048

GRB 080727A: Early IR observations
2008-07-29T15:12:05Z (16 years ago)
Andrew Levan at U.of Leicester <>
A.J. Levan (U. Warwick) and K. Wiersema (U. Leicester) report for a 
larger collaboration:

We observed the location of GRB 080727A (Immler et al. GCN 
8021) using UKIRT. A series of K-band exposures were taken beginning at
06:24:51 UT, roughly 30 minutes after the burst, a total of 720s
of observtions were taken (36x20s).  We find no evidence for any
source within the XRT error circle (Evans et al. GCN 8025) for GRB
080727A, down to a limit of K=19.8 mag (3-sigma).

Comparing this limit to the extrapolated X-ray flux 30 minutes
post-burst implies that the observed X-ray to optical/IR spectral
slope was beta_KX < ~0.8, thus the non-detection in the IR is likely
down to the rapid fading of the afterglow, rather than suppression
of the optical/IR flux.

We thank the staff of UKIRT for their rapid response to these alerts.
Looking for U.S. government information and services? Visit