Most big, heavy stars die in violent explosions. But some are more violent than others. The most powerful produce cosmic “death rays” — beams of energy that could kill any living thing within thousands of light-years.
A gamma-ray burst may form when the core of a heavy star collapses to form a black hole. Gases around the core form a swirling disk around the black hole. The disk gets so hot that it produces an outburst of gamma rays — the most powerful form of energy.
The gamma rays fire out through the poles of the dying star. These beams are incredibly powerful. They can emit more energy in a few seconds than the Sun will produce in its entire lifetime — about 10 billion years.
The beams of gamma rays are narrow, though, so we have to line up along one of the beams to see them. And our gamma-ray detectors have to be looking at the right time — most bursts last only a matter of seconds.
If we miss the gamma rays, though, we still see some impressive fireworks. The star’s outer layers blast into space as a hypernova — an especially powerful supernova. That part of the outburst can shine brilliantly for months.
Planets that line up close to the beam of gamma rays could be incinerated. And life on planets thousands of light-years away could be destroyed.
Fortunately, no likely future bursters are close enough to Earth to be a concern. But astronomers have identified a star that could produce a gamma-ray burst fairly soon. More about that tomorrow.
Script by Damond Benningfield