Discover the Universe’s Most ‘Pristine’ Object: The Incredible Primeval Star

Stars are like nature’s original fusion reactors. They merge hydrogen and helium, and in some cases, heavier elements, releasing energy as light and heat. However, the first stars existed in a simpler state, consisting mainly of the lightest elements. For a long time, scientists didn’t think we’d find such ancient stars. Recently, though, a team from the University of Chicago led by Alexander Ji discovered a star named SDSS J0715-7334. This star has an unusually low amount of metals—elements other than hydrogen and helium.

Located about 163,000 light-years away in the Large Magellanic Cloud, SDSS J0715-7334 is setting itself apart. The findings were shared in a paper on arXiv, though it’s still under review.

There’s a fascinating link between stars and us. Carl Sagan famously said we are made of “star stuff.” Stars evolve in generations, too. The earliest stars, mostly hydrogen and helium, exploded as supernovae, creating richer elements that formed the next generation. Astronomers have been on the lookout for the remnants of those first stars—called Population III stars—by searching for low-mass stars with low metallicity.

The discovery of SDSS J0715-7334 began with data from the Sloan Digital Sky Survey. The team later observed it using the Magellan telescope in Chile. While the James Webb Space Telescope has identified several early-generation stars, this one stands out. It has over ten times fewer metals than previous finds and notably low levels of carbon, possibly a first among similar discoveries.

The low carbon levels are intriguing. Most known metal-poor stars have higher carbon levels, which help cool them and prevent explosions. Anna Frebel, an astronomer from MIT, pointed out that the different carbon levels in stars could indicate varied cooling processes across the universe. “Different environments cool their gas differently at early times,” she noted. Understanding why is still a puzzle.

Continued searches for these primordial stars are essential. Each discovery could lead to significant insights about the universe’s early years and our cosmic origins.

Source link

Astrophysics,Stellar evolution