Impossibly huge black holes may have come from weird ancient stars

By Leah Crane

Of all the prevailing ideas for how black holes emerge, none could account for the existence of an impossibly large type of black hole detected in 2019 – but now we may know how it could have formed.

In May 2019, researchers at the Laser Interferometer Gravitational-Wave Observatory (LIGO) in the US and its Italian counterpart Virgo measured ripples in space-time called gravitational waves and determined that their signal was the result of two black holes merging.

Stellar-mass black holes like these arise when a star becomes …