GAMMA-RAY BURSTS AND AFTERGLOWS FROM ROTATING STRANGE STARS AND NEUTRON-STARS

We here discuss a new model of gamma-ray bursts (GRBs) based on differ entially rotating strange stars. Strange stars in this model and diffe rentially rotating neutron stars in the Kluzniak-Ruderman model can pr oduce extremely relativistic, variable fireballs required by GRBs and then become millisecond pulsars. The effect of such pulsars on expansi on of the postburst fireballs through magnetic dipole radiation is stu died. We show that these two models can explain naturally not only var ious features of GRBs but also light curves of afterglows. [S0031-9007 (98)07701-1].