Even now, 60 years after its discovery, the first black holes detected still plague astronomers. The giant star in the universe at the center of the Cygnus X-1 system is 50% larger than previously thought, making it the heaviest stellar black hole ever observed directly.
Based on new observations, an international team of researchers estimates that a black hole is 21 times the mass of our Sun and is spinning faster than other known black holes. With the recalculated weight, scientists are rethinking how bright stars that turn into black holes evolve and how quickly they shed their skin before they die.
The mass of a black hole depends on the characteristics of the parent star, such as the mass of the star and the amount of metal (the amount composed of elements heavier than the mass of the star). helium). Throughout the life of a star, it sheds its outer layers through a stellar wind explosion. Scientists believe that large stars rich in heavy elements release mass faster than small stars with low metal content.
“Stars lose mass to their surroundings due to the stellar wind blown off their surface. But to make a black hole so heavy and very fast, dial down the amount of mass a bright star loses throughout its life. Must be, “co-author of the study Ilya Mandel, an astrophysicist at Monash University in Australia. Said in a statement..
Distance is important
In a new study, researchers used a proven method to measure the distance of stars from Earth to estimate the mass of Cygnus X-1. parallax..So Earth Astronomers orbit the Sun and measure the visible movement of a star against a distant background. You can use a little trigonometry and use that movement to calculate the distance of a star from Earth.
In addition, the Cygnus X-1 black hole sucks in the outer layers of the star and slowly eats up its bright blue companion star, forming a bright disk that rotates around the black hole. When a substance falls into a black hole, it is heated to millions of degrees and emits brilliant X-ray radiation. Some of this material barely escapes black holes and is expelled by powerful jets that emit radio waves that can be detected on Earth.
The research team tracked these distinctive bright jets from the Very Long Baseline Array (VLBA), a continent-sized network of 10 radio telescopes across the United States from Hawaii to the Virgin Islands. Was used. Over the course of six days, they followed the complete trajectory of the black hole around its companion star, determining how much the black hole moved in space.
They found that Cygnus X-1 was about 7,200. Light year It is over the previous estimated 6,000 light-years from Earth. The updated distance suggests that the blue supergiant is brighter, heavier, and 40 times larger than the Sun than previously thought. And given the orbital period of a black hole, they were able to give a new estimate of the mass of a black hole — a whopping 21 solar masses.
“Using updated measurements of black hole mass and distance from Earth, we were able to confirm that Cygnus X-1 was spinning incredibly fast. Very close to light speed. “It’s faster than any other black hole found so far.” Lijun Gou, a researcher at the National Astronomical Observatory of China (NAOC), co-author of the study, said in a statement.
This finding is evidence of how increased sensitivity and accuracy of telescopes can unravel the mystery of even some of the most studied parts of our universe.
“As the next generation of telescopes come online, they will become more sensitive and the universe will become more and more detailed,” said Xueshan Zhao, a researcher at NAOC, who co-authored the study. Said in a statement.. “It’s a great opportunity to become an astronomer.”
Researchers detailed their findings in a journal on February 18th Science..
Originally published in Live Science.
Astronomers Find the Fastest Rotating Black Hole Ever
Source link Astronomers Find the Fastest Rotating Black Hole Ever