Alternative Theories for Gamma-Ray Bursts

Several theories have tried to explain the most colossal eruptions in the universe. Here are the leading ideas:

White dwarf flares: Our Sun routinely ejects high speed material and radiation in solar flares. Very old compact stars called white dwarfs are known to flare as well, but the amount of energy is not enough to explain distant GRBs.

Starquakes: Neutron stars are packed so tightly that their surfaces may sometimes crack under the pressure. These seismic events have been detected, but it is unlikely one of these could release enough energy to be a GRB.

Merging neutron stars: Neutron stars sometimes come in pairs orbiting around each other. At some point the two will spiral into each other. The smash-up may explain short duration GRBs that last less than 2 seconds, but probably cannot explain the more common long duration GRBs.

Charged black holes: Black holes can be electrically charged, and their sudden discharge could power a GRB. But it's not clear how a black hole could gather enough charge to begin with.

Strange stars: The high density in neutron stars could transform normal matter into an exotic form of matter made of strange quarks. Such a conversion into a strange star could release loads of energy, but whether this could result in a GRB is highly speculative.

Cannonballs: Instead of a continuous jet, material could shoot from the central engine in chunks, or cannonballs. Although still debated, many scientists believe this model is ruled out by the data.

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