(CNN Spanish) – For the first time, astronomers have been able to capture the first image of the supermassive black hole at the center of our galaxy, the Milky Way, known as Sagittarius A*. The European Southern Observatory (ESO) reported It’s a statement That this image “provides irrefutable evidence that the object is indeed a black hole and sheds valuable clues to how it works”.
This image is the first direct observation that confirms the existence of Sagittarius A*, as the beating heart of this galaxy.
Black holes do not emit light, but the image shows their shadow surrounded by a bright ring, the light deflected by the black hole’s gravity. Astronomers have said that the black hole is four million times larger than our sun.
“For decades, astronomers have wondered what lies at the heart of our galaxy, as it pulls stars into tight orbits by its immense gravity,” Michael Johnson, an astrophysicist at the Harvard and Smithsonian Center for Astrophysics, said in a statement.
“In this picture, we are thousands of times closer to these orbits, where gravity grows a million times stronger. At this close range, a black hole accelerates matter to approach the speed of light and twists the paths of photons twisted (space-time)”.
Capture a black hole as a team
The image was taken by the Event Horizon Telescope (EHT), a formation Join the eight existing radio observatories around the planet to form a single “Earth-sized” hypothetical telescope, ESO explained. “The telescope is named after the event horizon, the edge of a black hole beyond which light cannot escape,” the observatory added. More than 300 researchers from 80 institutions have participated in this effort.
In fact, the image we know now about the Sgr A* black hole is an average of the various images that the EHT extracted from its 2017 observations.
📢 Latest news: Learn about the black hole at the center of our galaxy! Astronomers have revealed the first image of the supermassive black hole at the center of the Milky Way. The image was produced by a global research team Tweet embed 📷 EHT . Collaboration pic.twitter.com/Y4tlfmfL6k
– ESO Chile (ESO_Chile) 12 May 2022
The black hole is about 27,000 light-years away from Earth. Our solar system is located in one of the spiral arms of the Milky Way, which is why we are so far from the galactic center. If we could see this in the night sky, the black hole would look like the same size as a donut sitting on the moon.
“We were surprised by how well the size of the ring matched the predictions of Einstein’s theory of general relativity,” said Jeffrey Bauer, EHT project scientist, from the Institute of Astronomy and Astrophysics, Senya Academy, in Taipei.
“These unprecedented observations have greatly improved our understanding of what is happening at the heart of our galaxy, and provide new insights into how these giant black holes interact with their surroundings,” he added.
The results of this discovery were published Thursday in a special edition of Astrophysical Journal Letters.
I’m looking for a black hole
It took astronomers 5 years to capture and confirm this image and this discovery. Previously, scientists noticed stars orbiting some invisible massive objects in the center of the galaxy.
The 2020 Nobel Prize in Physics has been awarded to Roger Penrose, Reinhard Genzel and Andrea Geis for their discoveries about black holes. Among them, evidence shared by Ghez and Genzel about the mass of an object at the center of the Milky Way.
“We now see that the black hole absorbs gas and light around it, pulling them into a bottomless crater,” Ramesh Narayan, a theoretical astrophysicist at the Harvard and Smithsonian Center for Astrophysics, said in a statement. “This image confirms decades of theoretical work to understand how black holes feed,” he said.
This is the second image he’s been able to capture of a black hole. The first is the historic EHT that was able to capture images of M87* in the heart of the distant galaxy Messier 87, located 55 million light-years away, in 2019.
Although the two images look the same, arc A* is more than 1,000 times smaller than M87*.
“We have two completely different types of galaxies and two completely different masses of black holes. But near the edge of these black holes they look amazingly similar,” Cera Markov, co-chair of the EHT Science Council and professor of theoretical astrophysics at the University of California, Amsterdam, said in a statement.
“This tells us that[Einstein’s theory of general relativity]governs these things closely. And any differences we see more must be due to differences in the material surrounding black holes.”
Impossible to take a picture
Although the Milky Way’s black hole is closer to Earth, capturing its image was more difficult.
“Gas in the vicinity of black holes is moving at the same speed, roughly the same as the speed of light, around Sgr A* and M87*,” said EHT scientist Chi Kuan Chan, at the Steward Observatory, Department of Astronomy and Data Science. The institute at the University of Arizona said in a statement.
“But while gas takes days to weeks to orbit the larger M87*, the much smaller Sgr A* completes an orbit in just minutes. This means that the brightness and pattern of the gas around Sgr A* were changing rapidly as EHT watched. It was like trying to get an image Clear puppy chasing its tail fast.”
The global network of astronomers had to develop new instruments to allow the rapid movement of gas around Sagittarius A*. The image they obtained is the average of the various images the team took. Researchers at the California Institute of Technology explained that capturing the image of Sagittarius A* was like taking a picture of a grain of salt in New York City with a camera in Los Angeles.
“This image from the Event Horizon Telescope requires more than just taking a picture of telescopes on top of tall mountains. It is the product of technically challenging telescopic observations and innovative computational algorithms,” explained Catherine Bowman, researcher at Rosenberg and assistant professor at Rosenberg University. Computer Science, Mathematical Sciences, Electrical Engineering, and Astronomy at Caltech during a press conference.
Bowman also worked on the M87 image* in 2019. Although the image of Sagittarius A* may look blurry, “it’s one of the sharpest images ever,” Bowman said.
Each telescope was pushed to a limit, which is called the diffraction limit, or the maximum number of subtle features that can be observed.
“And that’s basically the level we’re looking at here,” Johnson said at the press conference. “It’s blurry because to make the image clearer, we need to move our telescopes away or move to higher frequencies.”
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