Skip to main content
New! October 18 GCN Classic Outage and Schema v4.2.0. See news and announcements

GCN Circular 2684

Subject
GRB 040827: UKIRT - 2nd epoch K-band imaging
Date
2004-08-29T16:16:33Z (20 years ago)
From
Nial Tanvir at IofA U.Cambridge <nrt@ast.cam.ac.uk>
N. Tanvir, R. Priddey (U. Hertfordshire) A. Levan (U. Leicester),
T. Geballe (Gemini) and T. Wold (JAC) report on behalf of a larger
collaboration:

We have obtained a 2nd epoch of K band imaging at UKIRT, 40 minutes
(again in ~0.6 arcsec seeing), starting at August 29.22 UT.

We confirm the findings of Kaplan and Berger (GCN Circular 2683),
that XMM-2 has faded by between 0.4 and 0.5 magnitudes, but similarly
caution that the photometry is quite sensitive to the chosen aperture
size (2.2 arcsec diameter was used) since the source is somewhat extended.

XMM-2 is therefore likely to be the GRB afterglow (+ host), and the
power-law decay slope a relatively shallow alpha~0.5, consistent with
a fairly significant host contribution to the measured magnitudes.

XMM-1 has remained constant at about K~19.8

This message may be cited.
Looking for U.S. government information and services? Visit USA.gov