A group of astronomers best known for debunking supposed black hole discoveries have now found one of their own. According to their own statements, they discovered the first inactive stellar black hole outside of the Milky Way. It also appears to have emerged from a star that simply collapsed with no sign of an explosion.
Dubbed VFTS 243, the black hole is at least nine times the mass of our Sun and orbits a hot, blue star 25 times our Sun’s mass. Both are in the Large Magellanic Cloud, a neighboring galaxy to the Milky Way.
“No plausible explanation” without a black hole
The black hole was discovered during a systematic analysis of 1000 massive stars in the so-called Tarantula Nebula, explains the European Southern Observatory. The stars below that could be accompanied by a black hole were sought. When a potential find was reported to VFTS 243, he was still very skeptical, says co-author Kareem El-Badry of the Harvard-Smithsonian Center for Astrophysics in the US. According to the announcement, he has earned the nickname “destroyer of black holes” because he has so often invalidated supposed discoveries. But this time it was different: “I couldn’t find any plausible explanation for the data that didn’t include a black hole,” he recalls.
Dormant or dormant black holes like VFTS 243 are comparatively difficult to spot because no material falls into them and emits telltale X-rays in the process. In addition, stellar black holes with few solar masses are also very small. For this reason, even considering there are tens of trillions of them in the observable universe, we don’t know much about such objects. The discovery of VFTS 243 therefore provides unique and valuable insights, including into the formation of these celestial bodies. It immediately poses a puzzle for the astronomers, because the star from which the black hole may have formed seems to have disappeared without any sign of an explosion. The research article on the discovery was published in the US journal Nature Astronomy.
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