Astronomers peering through the European Southern Observatory’s Very Large Telescope have spotted something extraordinarily rare: a double star, the surfaces of which have merged.
No double star quite like this has ever been seen, and it’s unusual to spot such a system because they are short-lived, the agency said in a release. Indeed, the double-star system—which is named VFTS 352 and located about 160,000 light years away in the Tarantula Nebula—will soon destroy itself in one of two ways, the scientists predict.
One possibility is that the two stars will merge, creating a super-massive, rapidly-rotating star. But this rotational energy will ultimately lead the system to become unstable. “If it keeps spinning rapidly it might end its life in one of the most energetic explosions in the universe, known as a long-duration gamma-ray burst,” said Hugues Sana, project lead scientist at Belgium’s University of Leuven. These types of explosions are the most powerful to have taken place since the big bang, according to Astronomy.com.
The second option is that the stars will stay “joined at the hip,” but not merge, and then separately explode on their own. “In the case of VFTS 352, the components would likely end their lives in separate supernova explosions, forming a close binary system of black holes,” or twin black holes, said theoretical astrophysicist Selma de Mink, from the University of Amsterdam.
In most examples of twin stars, one is bigger than the other, just due to chance; but this one is a rare instance where the stars are the same size. When one is larger than the other, it can strip away components of the smaller one, forming a so-called vampire star.