Astronomers have discovered an extremely rare star that offers a glimpse into the earliest days of the universe.
The star, named SDSS J0715-7334, is considered one of the most “pristine” stars ever found, meaning it contains almost none of the heavier elements that are common in stars today.
The discovery was made using data from the Sloan Digital Sky Survey V and follow-up observations with the powerful Magellan telescopes in Chile.
The study was published in the journal Nature Astronomy.
To understand why this star is so special, it helps to go back to the beginning of the universe. After the Big Bang, the universe was filled mostly with hydrogen and helium. The very first stars formed from these simple elements.
They burned very hot and lived short lives, producing heavier elements like carbon and iron before exploding and spreading those materials into space.
Later generations of stars, including our Sun, formed from this enriched material. That means most stars today contain a mix of many elements.
But SDSS J0715-7334 is different. It formed very early in cosmic history, likely as part of the second generation of stars, and still retains an almost untouched chemical makeup.
The research was led by Alexander Ji from the University of Chicago, along with a team that included undergraduate students. Using the survey data, they first searched for stars with extremely low amounts of heavy elements, often called “metals” by astronomers. They then used high-resolution observations from the Magellan telescopes to confirm their findings.
What they discovered was remarkable. This star has less than 0.005% of the metal content found in the Sun. It is even more metal-poor than previous record holders and shows especially low levels of iron and carbon. In fact, it contains about 40 times less iron than the most iron-poor star previously known.
The star is located about 80,000 light-years away from Earth. Data from the European Space Agency’s Gaia mission suggests it did not originally form in our Milky Way galaxy. Instead, it likely formed in a smaller galaxy and was later pulled into the Milky Way over billions of years.
Scientists are excited about this discovery because such stars act like time capsules. Since we cannot directly observe the very first stars anymore, these ancient, nearly unchanged stars provide important clues about how the first stars formed and how the universe evolved.
The discovery also highlights how modern astronomy works as a team effort. Large surveys like SDSS-V help scientists identify rare objects, while powerful telescopes like those at Las Campanas Observatory allow them to study these objects in detail.
For the students involved, this was more than just a research project. It was a chance to take part in a real scientific discovery, showing how curiosity and teamwork can lead to breakthroughs.
As scientists continue to search the sky, stars like SDSS J0715-7334 may help answer some of the biggest questions about our cosmic origins.
