Is the Afterglow of Gamma-Ray Burst GRB 021004 Unusual?

The bumpy light-curve of the bright optical afterglow (AG) of gamma ray burst(GRB) 021004, its spectral evolution and its radio emission have been claimedto be unusual. In the Cannonball Model of GRBs that is not the case. The veryearly AG's shape is, as for GRB 990123, a direct tracer of the expectedcircumburst density profile. The unprecedented precision of the data allows forthe ``resolution'' of two cannonballs (CBs) in the AG. These two CBs correspondto the two pulses in the GRB and to the two wide humps in the AG light curve.The smaller wiggles in the AG are, as for GRBs 000301c and 970508, to beexpected: they trace moderate deviations from a constant density interstellarmedium. The observed evolution of the optical spectrum is that predicted in theCB model. The X-ray and radio emissions of GRB 021004 are also normal.Comment: All observational data points reported to date in GCN notices and in astro-ph were included. Submitted to ApJ