The optical afterglow of GRB 000911: Evidence for an associated supernova?*
Institute of Astronomy, University of Cambridge, Madingley Road, CB3 0HA Cambridge, UK
2 Osservatorio Astronomico di Brera, Via Bianchi 46, 23807 Merate (Lc), Italy
3 Palomar Observatory, 105-24, California Institute of Technology, Pasadena, CA 91125, USA
4 Research School of Astronomy & Astrophysics, Mount Stromlo Observatory, Cotter Road, Weston, ACT 2611, Australia
5 Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, 50125 Firenze, Italy
6 SISSA/ISAS, via Beirut 4, 34014 Trieste, Italy
7 Università dell'Insubria, Via Lucini 3, 22100 Como, Italy
8 Osservatorio Astronomico di Roma, Via Frascati 33, 00040 Monteporzio Catone, Italy
Corresponding author: D. Lazzati, firstname.lastname@example.org
Accepted: 12 September 2001
We present photometric and spectroscopic observations of the late afterglow of GRB 000911, starting day after the burst event and lasting weeks. We detect a moderately significant re-brightening in the R, I and J lightcurves, associated with a sizable reddening of the spectrum. This can be explained through the presence of an underlying supernova, outshining the afterglow days after the burst event. Alternative explanations are discussed.
Key words: gamma rays: bursts / supernovae: general
Based on observations made with ESO Telescopes at the Paranal Observatories under programme IDs 65.H-0215 and 266.D-5620. Some of the data presented here were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation.
© ESO, 2001