2003A&A...406L..33D

We present photometric and spectroscopic observations of the gamma-ray burst GRB021211 obtained during the late stages of its afterglow. The light curve shows a rebrightening occurring ∼25 days after the GRB. The analysis of a VLT spectrum obtained during the bump (27 days after the GRB) reveals a suggestive resemblance with the spectrum of the prototypical type-Ic SN1994I, obtained ∼10 days past maximum light. Particularly we have measured a strong, broad absorption feature at 3770Å, which we have identified with CaII blueshifted by ∼14400km/s, thus indicating that a supernova (SN) component is indeed powering the ``bump'' in the afterglow decay. Assuming SN1994I as a template, the spectroscopic and photometric data together indicate that the SN and GRB explosions were at most separated by a few days. Our results suggest that GRBs might be associated also to standard type-Ic supernovae.