Vanishing Star

StarDate

A massive star in a nearby galaxy may have winked out of existence with little or no pyrotechnics. Instead of blasting itself to bits as a supernova, leaving behind a neutron star or black hole, it skipped the “blasting” stage. Instead, the entire star collapsed to form a black hole.

VFTS 243 is a binary system in the Large Magellanic Cloud, a companion galaxy to the Milky Way. One member is a star that’s about two dozen times as massive as the Sun, and more than 150,000 times brighter. The other is a black hole about 10 times the Sun’s mass.

A team of astronomers looked for evidence that the star that formed the black hole had exploded as a supernova – the likely fate of most stars at least eight times the Sun’s mass. The supernova forms when the star’s core collapses and its outer layers fall inward, then rebound.

Such a blast would leave a cloud of debris. It might also give the black hole a strong “kick” away from the companion star. The astronomers found no evidence of either. There was no debris from an explosion. And the bright star and the black hole follow an almost circular orbit around each other. That suggests there was little or no interaction between them when the black hole formed.

Almost the entire mass of the star must have collapsed to form the black hole. So the star that give birth to the black hole in VFTS 243 might simply have vanished from the sky.

Script by Damond Benningfield