Gamma-ray bursts are at great distances from Earth, yet Earth receives tremendous amounts of energy from them. Explain.
A) Gamma-ray bursts are supermassive stars, equivalent to 100,000 ordinary supernovae.
B) A gamma-ray burst represents the explosion of an entire galaxy.
C) The energy is released along jets rather than uniformly in all directions. If Earth is in the path of one of these jets, a gamma-ray burst is observed.
D) The gamma radiation from a burst is released in all directions, but then it is focused in the direction of Earth by gravitational lensing.

Question

Quizplus · Accepted Answer

Gamma-ray bursts release energy in highly directional jets. If Earth happens to be in the path of one of these jets, the burst is observed. This focused emission explains why, despite their great distances, the bursts are still detectable and can appear very bright from Earth.

Gamma-Ray Bursts Are at Great Distances from Earth, Yet Earth