Stellar merger model for gamma-ray burst

This sequence illustrates a model for the formation of a short-duration gamma-ray burst:

1. A pair of neutron stars in a binary system spiral together. Orbital momentum is dissipated through the release of gravity waves, which are tiny ripples in the fabric of space-time.
2. In the final milliseconds, as the two objects merge, they kick out highly radioactive material. This material heats up and expands, emitting a burst of light called a kilonova. An accompanying gamma-ray burst lasts just one-tenth of a second, but is 100 billion times brighter than the kilonova flash.
3. The fading fireball blocks visible light but radiates in infrared light.
4. A remnant disc of debris surrounds the merged object, which may have collapsed to form a black hole.

Links:

• NASA Press release
• Hubble captures infrared glow of a kilonova blast