A binary star system 8,000 light-years away from Earth is going to explode and produce a powerful gamma-ray burst.
Apep, named after the Egyptian god of chaos, is an interesting pair of luminous stars. The two stars are tearing each other apart, creating a violent swirl of dust around it. More excitingly, one of the stars is about to go supernova.
A team of astronomers from the University of Sydney in Australia discovered the binary star system. Their findings were published in the journal Nature Astronomy.
Apep's Chaos
"We discovered this star as an outlier in a survey with a radio telescope operated by the University of Sydney," shared Joe Callingham, lead author of the study. "We knew immediately we had found something quite exceptional: the luminosity across the spectrum from the radio to the infrared was off the charts."
At the heart of the binary system are two Wolf-Rayet stars that are very rare, very hot, very luminous, very old, and have the mass of at least 25 suns. The two stars orbit each other every one hundred years or so, producing stellar wind with a velocity as fast as 12 million kilometers per hour or about 1 percent of the speed of light.
The binary star system, however, caught the attention of the researchers because of the "stunning" dust plume surrounding it. Peter Tuthill, the research group leader, said that the team immediately knew that they have spotted a special kind of nebula called pinwheel when they saw its spiral dust tail.
The shape of its plume was caused by the orbiting stars at the system's heart. The process injects dust into the expanding wind, creating a pattern similar to water from a rotating garden sprinkler.
However, when measured, the team found something more startling. The rate of the expanding stellar wind is 10 times faster than the dust.
Most Violent Death
"What we have found in the Apep system is a supernova precursor that seems to be very rapidly rotating, so fast it might be near break-up," explained Benjamin Pope, the study's co-author from New York University.
A supernova is the explosion of a star. It is already one of the most powerful events in the universe but according to the researchers, the rapid rotation of the Wolf-Rayet stars in the system's core might produce an even bigger, more powerful event.
The study revealed that Apep is a candidate for the first-ever gamma-ray burst within the Milky Way Galaxy.
A gamma-ray burst shines million trillion times as bright as the sun. When it happens, although it lasts for only a few milliseconds to several minutes, it becomes the brightest source of cosmic gamma-ray photons in the universe.
The researchers are not certain the star system would create a gamma-ray burst. Tuthill warned that the orbiting stars might slow down and explode into an ordinary supernova.
However, when it does happen, people on Earth have nothing to be worried about. The gamma-ray burst, which could destroy the ozone layer, is not aimed at the planet.
