A star’s death is explosive, mystifying and out of this world – and now, scientists have figured out a way to watch it happen in real-time. Astronomers developed an “early-warning system” to alert scientists when a star is on the verge of dying in a supernova explosion. 

Until now, it’s been difficult for scientists to observe the moment a star explodes. But for the first time, researchers have simulated that sudden journey to a star’s demise. Researchers found that in a star’s “red supergiant” phase – the last phase of its life – dense material accumulates around it and the star becomes drastically dimmer.

“The dense material almost completely obscures the star, making it 100 times fainter in the visible part of the spectrum,” Ben Davies, lead author of the study, said in a press release. “This means that, the day before the star explodes, you likely wouldn’t be able to see it was there.” 

Prior to the new research, which was published in Monthly Notices of the Royal Astronomical Society on Thursday, astronomers were unsure how long it took that sort-of “cocoon” of dense material to gather. Most late-life images of stars are from about a year before they explode, Liverpool John Moores University’s Astrophysics Research Institute said in a press release. But in those images, the stars aren’t surrounded by material; they just look normal. 

That means that it takes less than a year for that shell of debris to gather and the supernova to occur. They also found that “red supergiants” undergo a “mass-losing event” shortly before they explode, a situation that “radically alters” their appearance. 

Basically, scientists found, the tell-tale sign of a supernova is that the star will “dramatically change.”

“Until now, we’ve only been able to get detailed observations of supernovae hours after they’ve already happened,” Davies said. “With this early-warning system we can get ready to observe it in real-time, to point the world’s best telescopes at it, and watch the surface of the star getting literally ripped apart in front of our eyes.”

Li Cohen

Li Cohen is a social media producer and trending reporter for CBS News, focusing on social justice issues.