A group of scientists has been searching for the truth about giant and luminous stars that mysteriously vanished from the sky.
According to widely accepted theory, stars have a finite lifespan and will eventually die. This is a spectacular death known as a supernova, where a star explodes and scatters its inner material across the universe.
However, scientists have found some large stars that disappeared without any signs of a supernova. They were clearly observed in older surveys, only to completely vanish in subsequent observations without any reasonable explanation.
Now, a pair of objects in a nearby galaxy may provide answers.
The VFTS 243 pair consists of a giant star and a mysterious black hole – (Photo: ESO).
According to Science Alert, the targeted pair is VFTS 243 in the Large Magellanic Cloud – a satellite galaxy of the Milky Way, the galaxy that contains Earth.
VFTS 243 consists of a black hole and a companion star. This system shows no signs of a supernova explosion that should accompany the formation of a black hole.
An international research team led by astrophysicist Alejandro Vigna-Gómez from the Niels Bohr Institute (Denmark) and the Max Planck Institute for Astrophysics (Germany) has proposed the most compelling explanation: In addition to a spectacular death, giant stars can also have a type of sudden demise.
“If someone were to look up at such a star about to completely collapse, at just the right moment, it could appear to suddenly turn off and disappear from the sky,” Dr. Vigna-Gómez said.
So what do stars become after they die?
Theoretically, after stars first explode into a supernova, their cores will collapse into neutron stars or white dwarfs depending on their size.
After some time, these neutron stars or white dwarfs may continue to explode and this time only leave behind a black hole or a nebula.
According to a new model, giant stars are entirely capable of “burning through the stage,” meaning that instead of exploding, the core – under the extreme gravitational pressure of its own – collapses directly into a dark black hole.
The black hole of VFTS 243 could have formed this way. This black hole has a mass ten times that of the Sun, accompanied by a star approximately 7.4 million years old with a mass about 25 times that of the Sun.
The new study has determined that these two objects have been orbiting each other in a nearly circular orbit.
This is the clearest evidence that this black hole has not been displaced from its original position by any supernova explosion while it was still a star.
This means that the ancient star did not necessarily explode into a supernova but rather underwent a failed explosion. It is highly likely that the remnants of the star were also “cleaned up” due to the sudden formation of the black hole, leaving nothing observable in the sky.
