Is there a 1998bw-like supernova in the afterglow of gamma ray burst   010921?
  We use the very simple and successful Cannonball Model (CB) of gamma ray bursts (GRBs) and their afterglows (AGs) to analyze the observations of the strongly extinct optical AG of GRB 010921 with ground-based telescopes at early times, and with the HST at later time. We show that GRB 010921 was indeed associated with a 1998bw-like supernova at the GRB's redshift. 
Shlomo Dado, Arnon Dar and Alvaro De Rujula