News

Astronomers discover the most distant star ever seen by humans


Astronomers have discovered the most distant star yet, a super-hot, super-bright giant that formed nearly 13 billion years ago at the dawn of the cosmos.

But this luminous blue star is long gone, so massive that it almost certainly exploded into pieces just a few million years after it emerged. Her “rapid” disappearance makes it all the more incredible that an international team was able to spot her thanks to the Hubble Space Telescope observations.

We see the star as it was around 12.8 billion years ago, which puts it around 900 million years after the Big Bang“, said astronomer Brian Welch, PhD student at Johns Hopkins University and lead author of the study that appeared in Wednesday’s review. Nature magazine.

He nicknamed him Earendel, an Old English name meaning morning star or rising light -“an apt name for a star we observed at a time often referred to as “cosmic dawn“.

A special technique

The former record holder, Icarusalso a blue supergiant spotted by Hubble, formed some time ago 9.4 billion years old. It’s more than 4 billion years after the Big Bang.

In both cases, the astronomers used a technique known as gravitational lensing to magnify tiny starlight. The gravity of galaxy clusters closer to us – in the foreground – serves as a lens to magnify smaller objects in the background. Without it, Icarus and Earendel would not have been discernible given their vast distances.

While Hubble spied galaxies 300-400 million years away from the Big Bang forming the universe, but their individual stars are impossible to spot.

“Usually they’re all stuck together… But here nature gave us this single star – very, very magnified, magnified by thousands of factors – so that we could study it.“, at said NASA astrophysicist Jane Rigby, who participated in the study. “It really is such a gift from the universe.”

According to an astronomer, Earendel may well have been part of the first generation of stars born after the Big Bang.

massive star

Current data indicates that Earendel had more than 50 times the size of our sun and about 1 million times brighter, surpassing Icarus. This galaxy probably survived, albeit in a different form after merging with other galaxies.

Earendel may have been the prominent star in a two-star, or binary, or even a three- or four-star system, one of the astronomers said. “There’s a slim chance it’s a black hole, although observations collected in 2016 and 2019 suggest otherwise.“, he noted.

The star lasted barely a few million years before exploding in a supernova that went unnoticed as most do. The most distant supernova observed by astronomers to date dates back 12 billion years.

By studying the stars, astrophysicist Jane Rigby said: “We literally understand where we came from because we are made up of some of this stardust.”

Related Articles

Leave a Reply

Your email address will not be published.

Back to top button