Questão 1914492

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Hubble: 'Single star' detected at record-breaking distance. They've nicknamed it "Earendel" and it's the most distant, single star yet imaged by a telescope.

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The light from this object has taken 12.9 billion years to reach us.

It's at the sort of distance that telescopes normally would only be able to resolve galaxies containing millions of stars.

But the Hubble space observatory has picked out Earendel individually by exploiting a natural phenomenon that's akin to using a zoom lens.

It's called gravitational lensing and it works like this: If there is a great cluster of galaxies in the line of sight, the gravitational pull from this mass of matter will bend and magnify the light of more distant objects behind.

Usually, this is just other galaxies, but in this specifi c case Earendel was in a sweetspot in the lens eff ect.

"We got lucky. This is really extreme; it's really exciting to fi nd something with such a high magnifi cation," said Brian Welch, a PhD student from Johns Hopkins University in Maryland, US. "If you happen to hit that right sweetspot, like we have in this case, the magnifi cation can grow up to factors of 1000s," he told BBC News.

The name Earendel comes from an Old English word meaning "morning star" or "rising light". We are seeing it a mere 900 million years after the Big Bang, or at a time when the Universe was only 6% of its current age.

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A fascinating piece of speculation surrounding Earendel is its composition. There is a way the data can be interpreted to suggest it is a pioneer star, an object made from the pristine gas created in the Big Bang.

Theory tells us that the very fi rst stars to shine in the Universe comprised only hydrogen and helium. Astronomers call them Population III stars. Only when these stars and their descendants had fused heavier elements did the cosmic environment change to the one we recognise around us today. But a 50-solar-mass star would only burn for a very short time, perhaps a million years at most before it ran out of fuel and collapsed and died. For a pioneer star to exist 900 million years after the Big Bang, it would need to have grown out of a long-surviving,solated and unpolluted cloud of gas. Not impossible, but arguably a stretch too far.

"Yes, we expect that Earendel is more likely to be a star that has been a little bit enriched in heavier elements, but not so much as the local stars around us today," Mr Welch said.

"There is a small chance that it's a Population III star. A few other studies predict you could get them in the outskirts of some galaxies. But that's something we're going to need much more detailed follow-up from other telescopes such as James Webb."

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https://www.bbc.com/news/science-environment-60931100 (Adapted)

Concerning the odds of Earendel being a Population III star, according to the text they are…