Fireballs and cannonballs confront GRB 991208

The broad band afterglow of GRB 991208 provides a good case for a three-sided confrontation: the data, the generally-accepted fireball models of GRBs, and the cannonball (CB) model. Follow-up radio measurements for this GRB have been recently reported. These new data challenge the fireball models and disagree with their predictions, based on earlier broad-band observations. but they are in very good agreement with the predictions of the CB model, based on the same earlier data, and involving many fewer parameters. (C) 2003 Published by Elsevier Science B.V.