Astronomers have mapped one of the largest structures in the universe, long hidden behind the Milky Way’s “evasion zone.”

Astronomers have finally revealed a map of a mysterious supercluster of galaxies that has been almost completely hidden from Earth since its discovery a decade ago. The results revealed that the structures were much larger than we realized and currently rank among some of the most massive objects in the known universe.

The Bella Supercluster is a collection of at least 20 galaxy clusters, each containing hundreds or thousands of galaxies, all bound together by gravity into a single entity. Despite its enormous size, this supercluster was only discovered in 2016 thanks to its location. The supercluster lies about 800 million light-years from Earth in what experts call the “evasion zone.” This region is the part of the night sky where the Milky Way is visible, and the Milky Way is so filled with stars and dust that it’s almost impossible to see what’s behind it.

The supercluster was originally called Terra incognita, Latin for “uncharted land,” but its cosmic hiding place prevented researchers from determining its true size.

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But in a new study uploaded to preprint server arXiv on March 10, researchers roughly mapped the Bella supercluster by measuring the motion of galaxies in and around the group’s edge.

The researchers said in a statement that they found that the structure is about 300 million light-years across (about 3,000 times the diameter of the Milky Way) and contains an enormous amount of material equivalent to about 30 quintillion suns. The new map also shows that most of this mass is distributed between two cores that move towards each other.

The research team is “delighted” to confirm that the supercluster is “a consistent large-scale structure comparable in size and mass to some of the largest and best-known superclusters in the local universe,” study co-author Lenny Krahn-Korteweg, an astronomer at the University of Cape Town who specializes in escape zones, told Live Science in an email.

Krahn-Korteweg said the Bella supercluster is now believed to be more massive than the supercluster Laniakea, which includes Earth and the rest of the galaxy, and is “a close second” to the Shapley supercluster, widely considered the largest supercluster in the galaxy. (Other structures, such as the Great Wall of Hercules and the recently discovered “Quip” are even larger, but they are thought to be one step above superclusters: clusters of superclusters.)

The researchers also gave the supercluster a new nickname: Bela Bunge. This means “widely revealing” in the Xhosa language used by South Africa’s indigenous people, where most of the telescopes used in the study were used.

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The avoidance zone has long puzzled astronomers who want to know what lies behind the Milky Way’s thick disk of stars, gas, and dust that covers up to 20% of the visible night sky.

“The millions or billions of stars that form the disk are extremely dense. [and so] “Because it’s so close to the galactic plane, we can’t easily see through it. Additionally, where there are stars, there are also lots of very small dust particles. Just like stars, this dust layer also gets thicker and thicker as we get closer to the galactic plane,” Krahn-Korteweg wrote.

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To get around this, the researchers combined 65,000 existing galaxy distance measurements with about 8,000 new redshift observations of other galaxies. (Redshift measures how fast something is moving away from Earth by calculating how far light is being stretched by the expansion of the universe.)

The most important of these observations are the nearly 2,000 redshift measurements captured by the MeerKAT telescope in South Africa, which detects radio waves emanating from the giant clouds of hydrogen gas that pervade most galaxies. This allowed the research team to directly measure the movement of galaxies within Vera, which had previously been impossible to observe using visible light.

Researchers believe that in the future, more powerful radio telescopes may be able to create a more accurate map of the Bella supercluster. But not all galaxies contain enough hydrogen that we can see, so parts of the structure are likely to always “remain partially obscured by us,” Krahn-Korteweg said.

A deeper understanding of the universe’s largest structures can help astronomers confirm cosmological models. However, to do this, we need to know both the size and speed of these objects, so the new discovery is very interesting.

“To understand one, you have to know the other,” Krahn-Korteweg said. “And if we had both, this is what we would be.” [able] This is to see if these observations can be matched with models of the universe. ”