Published on Nov 20, 2018
University of Sydney astronomers, working with international colleagues, have found a star system like none seen before in our galaxy. The scientists believe one of the stars—about 8000 light years from Earth—is the first known candidate in the Milky Way to produce a dangerous gamma-ray burst, among the most energetic events in the universe, when it explodes and dies. The system, comprising a pair of scorchingly luminous stars, was nicknamed Apep by the team after the serpentine Egyptian god of chaos. One star is on the brink of a massive supernova explosion. The findings, published today in Nature Astronomy, are controversial as no gamma-ray burst has ever been detected within our own galaxy, the Milky Way. Yet in the southern constellation of Norma, nestled just beneath Scorpio's tail, astronomers have discovered this uniquely beautiful star system. At its heart, wrapped in an elegantly sculpted plume of dust and gas, lies a powerful binary pair. The two hot, luminous stars—known to astronomers as Wolf-Rayets - orbit each other every hundred years or so, according to the research conducted at the Sydney Institute for Astronomy. This orbital dance is embossed on a fast wind streaming off the stars. Using spectroscopy, the astronomers have measured the velocity of the stellar winds as fast as 12 million kilometres an hour, about 1 percent the speed of light.