The black hole is only 1,500 light-years away from Earth.
A black hole is one of the smallest black holes discovered to date. Researchers write this in the journal Monthly Notices of the Royal Astronomical Society.
The black hole has been nicknamed the “unicorn”. On the other hand, the black hole owes its nickname the fact that it can be found in the constellation of the same name. But the researchers also thought the title was apt, because a black hole is so unique.
A black hole is only 3 times heavier than our Sun, which makes it small relative to a black hole. Very few black holes of this small mass have been discovered so far. Additionally, the black hole is very close to our solar system.
Although the black hole is very close to Earth, astronomers have not noticed it yet. It’s easy to explain. Black holes are – as the name suggests – black. They have such an immense cuteness that nothing can escape. Not even the light. This makes black holes practically invisible. But what researchers can see in this case is the red giant that accompanied the black hole. Several telescopes have already examined this star. The researchers looked at the data collected by these telescopes and quickly noticed that the star was changing shape as it wandered down its lanes. The changes the star has undergone strongly indicate that “something” was attracting the red giant. “We calculated that a companion (Red Giant, Liberator) should be about three times the mass of the Sun,” says researcher Tharindu Jayasinghe. Scientias. The idea that it could be a black hole was quickly rejected not long ago. It was recently thought that black holes of little solar masses do not exist. But researchers have reverted to it. Thus, Jiaxing and colleagues also considered the possibility that the red giant was accompanied by a small black hole. After studying all the possibilities, only one remained. “We argue that there should be a dark compressed object in this system,” says Jayasinghe. The simplest and most likely explanation is the existence of a small-mass black hole.
Just as the Moon’s gravity affects Earth’s oceans and causes tides, a black hole pulls the star with its gravity, causing it to deform. The red giant orbiting this small black hole is not circular, but rather a drop shaped due to the gravitational pull of this black hole. Usually, black holes (heavier) reveal their location by emitting X-rays. It attracts stars with its great attraction and extracts gas from those stars. The gas collects in a so-called accretion disk around a black hole. The material inside the disc rotates faster than the material under the disc, which creates friction, which in turn creates x-rays that can be observed with an X-ray telescope. Researchers have long suspected that there are (smaller) black holes that barely interact with orbiting stars, and thus produce little or no X-rays. In the new study, researchers demonstrated the existence of such black holes and immediately revealed how we can detect them using stars orbiting them.
“The mass of the black hole is 3.04 (+/- 0.06) solar masses and is located 1,500 (+/- 23 light years) from Earth,” says Jayasinghe. “It is one of the smallest black holes known to us, and it is very likely the smallest black hole that has been discovered in our Milky Way galaxy so far.” With a mass of about 3 solar masses, a black hole is located between the heaviest neutron stars (about 2.2 solar masses) and the lightest X-ray black holes (about 5 solar masses). “Objects in the gap (between heavy neutron stars and black holes that emit x-rays of light, ed) are rare!” Jayasinghe confirms. The discovery of these black holes, whose location is not revealed by X-rays, is of great importance. “It helps researchers better understand how black holes form and how they are distributed across the Milky Way.”
Researchers have already started their studies. It remains to be seen whether it will lead to the discovery of tiny black holes closer to Earth in the near future. But Jayasinghe definitely doesn’t rule it out. It is also unclear whether lighter black holes are waiting to be discovered. Massive stars are dying – at least eight times the mass of our Sun – turning into neutron stars or black holes. The boundary between the heaviest neutron stars and the lightest black holes is unknown to astronomers. “It’s somewhere between 2.2 and 5 solar masses,” says Jayasinghe. “In theory, the maximum mass of neutron stars appears to be about 3 solar masses – but in reality, it might be a bit less. So the unicorn is really one of the smallest possible black holes.” Look for black holes with a similar mass – or maybe a little smaller – as the unicorn continues in the meantime. It is hoped that the discovery of more objects between the heaviest neutron stars and the lightest X-rays by mass will provide more insight into the formation of black holes and neutron stars.
It looks like more black holes between 3 and 5 solar masses will be discovered. “(This study, ed.) Tells us that there are many black holes that do not interact directly with their stars, waiting to be discovered,” said Jayasinghi. “Our results indicate that there are as many as 100 to 1,000 unicorn-like systems in the Milky Way.”
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