Astronomers have discovered a hitherto unseen star from Earth

Astronomers have discovered a hitherto unseen star from Earth

(Cape Canaveral) Astronomers have discovered a hitherto unseen distant star from Earth, the super-hot, super-bright giant that formed at the dawn of the universe about 13 billion years ago.

Released at 1:39 p.m.

Marcia Ton
Associated Press

But this glowing blue star no longer exists because it was so large that it erupted only a few million years after its birth. It is noteworthy that its brief existence was discovered by an international team based on observations made by the Hubble Space Telescope. The light emitted by distant stars takes unimaginable time to reach us.

“We see the star about 12.8 billion years ago, or about 900 million years after the Big Bang,” said Brian Welch, PhD student at Johns Hopkins University, the primary author of a study published Wednesday by renowned science. Magazine Natural.

“We are definitely lucky,” he added.

He called the star Earendel, an Old English word meaning morning star – “the appropriate name for a star we notice at a time is ‘Cosmic Dawn’.”

The oldest known star, Icarus, was discovered by Hubble. It formed 9.4 billion years ago, more than four billion years before the Big Bank.

In both cases, astronomers used a technique called “gravitational lensing effect” to amplify very low light. The gravitational pull of the galaxies closest to us – in the foreground – acts as a magnifying lens for small objects in the background. Otherwise, Icarus and Earendel would be invisible due to their vast distances.

If Hubble had observed galaxies 300 or 400 million years after the Big Bang, it would not have been possible to identify their individual stars.

“Unless they stick together … but here nature has given us a star – very, very, many thousands of times – for us to study,” said NASA astronomer Jane Rigby, who took part in the study. . It is a beautiful gift from the universe. ⁇

Vinicius Blaco of the National Science Foundation called the discovery “wonderful.” He did not participate in the study.

Based on Hubble data, Blaco says Airtel, the first generation of stars born after the Big Bang, could be much better. Upcoming observations of the brand new James Webb Space Telescope should provide more details and “give us a new part of this cosmic mystery of the evolution of our universe,” he added.

Current data indicate that Erendel is 50 times larger than our Sun, a million times brighter, and the dwarf Icarus. The small, immature Earendel galaxy is nothing like the spiral galaxies photographed anywhere else, but it is like a “total object,” Welch said.

Unlike the Earendel, this galaxy may have survived, but remains in a different shape after merging with other galaxies, he said.

“It’s like a small snapshot of the past,” he said.Me Rickby.

Welch said Erendel could be the dominant star in a system of two or three or four. Although observations made in 2016 and 2019 do not point in that direction, it has a small chance of being a black hole.

Whoever its neighbor was, the star survived only a few million years ago and erupted into a supernova that went unnoticed. The most distant supernova observed by astronomers is 12 billion years old.

The web telescope, which is a hundred times more powerful than Hubble, will help clarify how big and hot this star is and tell us a little more about its galaxy.

In studying the stars Mr.Me Rigby: “Because we’re made of this stellar powder we really understand where we’ve come from.”

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