Dying star could unleash a powerful gamma-ray burst in our galaxy

Published in the academic journal Nature Astronomy, an international team of researchers reveals their findings on a star system 8,000 light-years from Earth, called Apep. They believe Apep contains a start that will one day produce one of the most powerful explosions in the universe, known as a gamma-ray burst.

Gamma-ray bursts have been observed in other galaxies, but never in our own. These powerful explosions come in two types: long-duration and short-duration. They can give off more energy in a few seconds than our sun will in its entire lifetime. They are so powerful, that it's believed a gamma-ray burst could be behind an extinction event on Earth about 450 million years ago.

In 2012, astronomer Joe Callingham, then working on his Ph.D at the University of Sydney, booked time on the European Southern Observatory's Very Large Telescope in Chile where he discovered a beautiful pinwheel. It's believed that the curved tails of Apep form as the two stars orbiting at the centre throw dust into the expanding winds, almost like a rotating lawn sprinkler.

The researchers suggest at the heart of the pinwheel are two massive Wolf-Rayet stars with winds that collide in the centre and produce dust. They calculate the winds are travelling at almost 12 million kilometres an hour, or one per cent of the speed of light. One of the stars is at the end of its life, and will undoubtedly die in a powerful explosion, called a supernova. Wolf-Rayet titan stars are the size of more than 20 times that of Earth’s sun but live only a few million years, compared to stars like our solar system’s, which live for 10 billion years.