Jet Cocoon (IMAGE) Spanish National Research Council (CSIC) Caption This is an artist representation of the hypernova. The interaction of the jet with the outer layers of the star forms a cocoon that surrounds the head of the jet and begins to propagate laterally with respect to the direction of the jet. The jet is capable of completely perforating the envelope of the parent star, emitting high energy gamma rays, responsible for GRB Credit Anna Serena Esposito Usage Restrictions Anna Serena Esposito License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.