European astronomers have put out something of a retraction: that black hole said to be the closest to Earth ever found—well, it doesn't exist. They're not too bothered, however. European Southern Observatory emeritus astronomer Dietrich Baade, co-author of the new research, says their error led to a find "even more exciting," per the Guardian. Researchers first announced the discovery of a black hole some 1,000 light-years away in 2020, saying it was the only explanation for the warped orbit of a star in the constellation Telescopium. They noted a second star with a wider orbit in the same HR 6819 system—which should've been of similar brightness, age, and mass as the first star—seemed unaffected. But HR 6819 is not as it first appeared.
This was confirmed after researchers teamed up with critics, including Dr. Julia Bodensteiner of KU Leuven in Belgium, who offered an alternative explanation. They believed the second star to be a stellar "vampire," stealing mass from its neighbor. If a black hole did exist, the two stars should be far apart, but new telescope data indicates they're close. "Since we saw that only one of the stars was whirled around at high velocity by some massive object, which we didn’t see, we assumed this unseen massive object to be … a black hole," Baade explains, per the Guardian. But "because the stripped star had lost most of its mass, the second star can reel it around quite easily while its effect on the other star is equally easily missed."
"The stripped star is even more exciting than the black hole because it was caught in a phase that lasts only a very small fraction of the total lifetime of the system," Baade tells the Guardian. More importantly, the stripping allows astronomers to peer into "the inner part of the star," to the source of "the energy that it is radiating away and has synthesized new elements," which might eventually form new stars or planets. The latest study is published in Astronomy & Astrophysics. CNET suggests the title of the closest black hole to Earth should now go to one of the smallest ever observed; it's located some 1,500 light-years away "in the shadow of red giant star V723 Mon." (Read more black hole stories.)