Astronomers have discovered one of the oldest stars that formed in another galaxy

Most of them Stars The universe is the result of tens of thousands of generations. But so far no one has been able to see it directly Stars First generation.

Scientists have reported a unique discovery: a Estrella The second generation was created first Galaxy Different from us.

Stellar Archaeology

First generation Stars Changed the universe. Within their nuclei, simple hydrogen and helium combined into a rainbow of elements. While you are Stars They died and exploded, sending these new elements across the universe. Elements such as iron, calcium or sodium, which are part of the human body. No one could find those first-generation stars, but they left their mark on their successors, as new research has found.

“We've developed an idea of ​​what these are Stars Chemically concentrated first StarsBut we still don't know if some of these signatures are unique or if something similar happened to others Galaxies“Anirudh City is a post-graduate and first faculty member at the University of Chicago A paper announcing the findings was published in the journal Nature Astronomy.

Citi specializes in so-called stellar archaeology: how the first generations are reconstructed Stars They changed the universe. “First we want to understand what their properties are Stars And what are the components they made,” he said.

But so far no one has been able to see them directly. Stars The first generation, if left in the universe. Instead, Chitty and his colleagues are looking Stars Formed from the ashes of that first generation.

It's a tough job because even the second generation Stars It is now incredibly old and rare. Most of them Stars The universe, including our own Sun, is the product of tens of thousands of generations, accumulating more and more heavy elements.

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“Maybe less than one in 100,000 Stars The Milky Way is one of these Stars The second generation, “You're really pulling needles out of haystacks.”

But it's worth it to get snapshots of what the universe looked like at that time. “In their outer layers, these Stars They preserve the elements near where they formed,” he explained. “If you can find a very old star and get its chemical composition, you can understand what the chemical composition of the universe was when it formed. Estrellabillions of years ago.”

The case of the Large Magellanic Cloud

For this study, Chitti and his colleagues pointed their telescopes at an unusual target: the Stars This forms the Large Magellanic Cloud.

The Large Magellanic Cloud is the brightest swath of stars visible to the naked eye in the southern hemisphere. We now think that it was an individual galaxy that was captured by the Milky Way's gravity a few billion years ago. This makes it particularly interesting because Stars The primitives formed outside the Milky Way give astronomers a chance to learn whether conditions in the early universe were all the same or different elsewhere.

Scientists looked for evidence of this Stars Especially the oldest ones in the Large Magellanic Cloud and cataloged ten of them, first by the European Space Agency's Gaia satellite and then by the Magellanic Telescope in Chile.

One of these Stars iIt immediately stood out as an oddity. It had many, many less heavy elements than any other star seen so far in the Large Magellanic Cloud. This means that it was probably created by the first generation StarsSo during repeated stellar births and deaths it did not accumulate more heavy elements.

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While mapping its elements, scientists were surprised to find that it contains less carbon than iron than we see. Stars of the Milky Way.

“It's very intriguing and the first-generation carbon enhancement is not as universal as we see in the Milky Way,” City said. “We need to do more studies, but this suggests there are differences from place to place.

“I think we're completing the picture of what the initial process of enriching the elements looked like in different contexts,” he said.

Their findings confirmed other studies that suggested the Large Magellanic Cloud produced very little. Stars Compared to the Milky Way.

Currently, Citi is running an imaging project that will map and detect much of the southern sky Stars soon. “This finding suggests there must be more of these Stars If we look closely, in the Large Magellanic Cloud,” he said. Stars “Chemically enriched the universe in different regions.”

(with information from Europa Press)

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