GCN Circular 2602
Subject
GRB 040511, very fast decay?
Date
2004-05-20T22:07:46Z (20 years ago)
From
David Bersier at STScI <bersier@stsci.edu>
D. Bersier, J. M. Castro Cer�n, J. Rhoads, A. Fruchter (STScI), A. Levan
(U. of Leicester), J. Gorosabel (IAA-CSIC), C. Kouveliotou (NASA/MSFC,
NSSTC), S. Patel (USRA, NSSTC), M. Merrill (NOAO), J. Bally, J.
Walawender, (U. Colorado), and B. Reipurth (Hawaii) report on behalf of
a larger collaboration:
We have observed the field of GRB 040511 (GCN Dullighan et al. 2004, GCN
2588) with the CTIO 4m telescope on the nights of May 11 and May 12.
Our R-band photometry of the candidate afterglow (Fox et al. 2004, GCN
2597) shows that this source decayed by 2.5 mag between 0.79d and 1.60d
after the burst. Assuming that the decay follows a power law, we derive
an index of -3.2. If the variable source is indeed the afterglow of GRB
040511, this would be among the fastest decay indices ever observed.