A new stellar-mass black hole is 9 times heavier than the Sun and is located in the Milky Way's neighboring galaxy, the Large Magellanic Cloud.
Scientists believe that dormant black holes are quite common in the universe, but they are incredibly difficult to detect due to the fact that they are inactive. But an international team of astronomers, using the powerful ground-based VLT telescope in Chile, managed to detect a binary system consisting of a sleeping black hole and a companion star – a blue supergiant, reports The Guardian.
Sleeping black holes of stellar mass, astronomers call black holes that do not show their activity. That is, they do not absorb the matter around them, for example, coming from stars that are too close. If there are no objects around such a black hole that could “eat” a black hole, then it does not emit X-rays and, accordingly, it is incredibly difficult to detect. It is believed that over time such black holes “wake up” and this can lead to destabilization of the orbit of a neighboring star, which will eventually lead to its absorption by a black monster.
A new sleeping black hole
The new binary system, which includes a sleeping black hole and its companion star, a blue supergiant with a mass 25 times that of the Sun, has been named VFTS243. The black hole itself in this system does not absorb the matter of the neighboring star and the mass of this black hole is 9 times the mass of the Sun.
Scientists have been looking for a sleeping black hole outside the Milky Way for several years and finally they succeeded, and they discovered a similar object in the Tarantula Nebula, which is located in our neighboring galaxy – the Large Magellanic Cloud.
A needle in a haystack sen
“This is a truly incredible discovery. It is the first stellar mass dormant black hole that we have been able to detect outside the Milky Way, although we had several candidates for this title. Our discovery is important for understanding how stars end their lives,” says Paul Crowther of the University of Sheffield, UK.
“We believe that in almost every galaxy there are billions of sleeping black holes. And the fact that we managed to find the first of them outside our galaxy can be compared to finding a needle in a haystack,” says Tomer Schenar from the University of Amsterdam, the Netherlands.< /p>
An unexpected discovery
According to scientists, stellar-mass black holes appear when huge stars collapse under by the action of its own gravity. The process of turning a star into a black hole is accompanied by a powerful supernova explosion. But as the study showed, this sleeping black hole formed without an explosion.
“The star from which this sleeping black hole emerged just disappeared, there was no supernova explosion. Confirmation of the theory that this can happen to stars appeared only recently. But our discovery provides the most accurate confirmation that stars can create black holes without supernova explosion,” Shenar says.
As Focus already wrote, recently scientists managed to make another important discovery that concerns black holes. Astronomers have discovered that in one of the spiral galaxies, more than 200 million light-years away, a black hole has not completely swallowed an already torn apart star. Scientists have discovered for the first time that as a result of incomplete absorption of stellar matter, a black hole can create huge clouds from the remnants of a star.
As for other important astronomical discoveries, scientists recently discovered one of the first galaxies in the Universe. This galaxy is the first of its kind, in which the speed of its rotation is now known. It turned out, as Focus already wrote, that this galaxy is much slower than the Milky Way and many other galaxies.