Are gamma-ray bursts powered by a star's collapsing magnetic fields?

When a massive star in a distant galaxy collapses, forming a black hole, two giant jets of light-emitting plasma shoot from its core. These extremely bright gamma-ray bursts (GRBs) are the most powerful explosions in the universe, and when a jet points towards Earth, the afterglow can be detected from ground and space-borne telescopes. Material does not simply catapult from an exploding star, it accelerates to ultra-high speeds along the narrow beam of the gamma-ray jet, leaving astrophysics puz...