According to National Geographic, the newly discovered black hole is located in the double star system HR 6819 in the constellation Telescopium in the southern hemisphere. According to calculations by astronomers, this newly discovered black hole is only 1,001 light-years from Earth, becoming the nearest black hole ever. Earlier, the black hole used to be considered closest to us in the star system A0620-00, 3000 light-years from Earth.
“This is a star system that has been studied by humans since the 1980s. However, it seems that it (the black hole) is right there that we don’t see it,” said Kareem El-Badry, a PhD student. at the University of California, Berkeley shared.
Photograph of star system HR 6819 (green, centered) from telescope. HR 6819 consists of 2 stars and 1 black hole
Accidentally discovered a black hole
The gravity of the black hole is so strong that even light cannot escape. Because it is impossible to observe directly, astronomers are forced to search for the existence of black holes by observing their gravitational effects on surrounding bodies. That’s how researchers stumbled upon this black hole.
Specifically, astronomers used the 2.2-meter MPG / ESO telescope at the La Shilla Observatory (Chile) to observe the HR 6819 star system to better understand binary star systems.
After closely observing the star system HR 6819 for several months, the orbital map of the stars was established by astronomers. However, the analysis data of star orbits made astronomers realize the appearance of an extremely gravitational object is ‘hidden’ in this star system.
The black hole in star system HR 6819 is smaller than some other black holes that exist in the universe. At a distance of 1,000 light-years, this black hole is not dangerous to the Earth. (Illustration)
Specifically, one of the two stars orbits an invisible object in a 40-day orbit, with tremendous velocity. Meanwhile, the remaining companion star lies at a much greater distance. After hypothesizing and calculating, this mysterious third object was concluded by researchers: this is a black hole.
“An invisible object with four times the mass of the Sun can only be a black hole,” said Thomas Rivinius, ESO scientist. “This star system contains a black hole closest to Earth ever.”
Notably, with such a close distance to Earth, astronomers who love the Southern Hemisphere can see the system of HR 6819 with the naked eye on clear days.
“We were completely surprised to realize that this is the first system containing a black hole visible to the naked eye,” said Petr Hadrava, a scientist at the Czech Academy of Sciences.
Scene in star system HR 6819: The star (blue) is orbiting an invisible black hole (red), while another star (blue) orbits at greater distances.
There may be millions of black holes ‘hiding’ inside Galaxy
To be able to detect black holes, scientists often have to track their most characteristic tracks. It is the X-ray, which is released by the black hole when they ‘gobble up’ matter from an unfortunate ‘flying’ star.
Thanks to this method, scientists have discovered the presence of black holes in the Milky Way.
However, scientists still believe that there are millions of black holes throughout the galaxy that do not emit X-rays. The newly discovered black hole in the star system of HR 6819 seems to be one of them. It doesn’t release X-rays when it ‘eats’ its companion stars.
“There are hundreds of millions of black holes out there, but we are completely unaware. Understanding what to look for will help us in our quest for black holes,” Rivinius said.
The first image shows a black hole 55 million light years from Earth, in the center of Messier 87.
Meanwhile, Dietrich Baade, an astronomer working at the Southern European Observatory, called the latest discovery “the tip of an extremely interesting sinking platform”.
In fact, ESO researchers turned to a binary star called LB-1, which is thought to be hiding a black hole.
“Perhaps more such star systems exist,” said Marianne Heida, another ESO astronomer.
“By searching and studying them, we can better understand the formation and evolution of stars that have been born eight times more massive than the Sun. A star of a size as large as or rather could create a supernova explosion at the end of its life cycle, before collapse itself to become a black hole. ”
Watch a video simulating the orbits of black holes and companion stars at HR 6819
Refer to Space.com