Astronomers may have identified the first generation of stars to form after the Big Bang, long-theorized Population III stars, made entirely of hydrogen, helium, and traces of lithium.
The discovery, led by Ari Visbal of the University of Toledo, comes from a detailed analysis of James Webb Space Telescope (JWST) data from a distant galaxy known as LAP1-B, according to a study published in The Astrophysical Journal Letters.
A perfect match for theory
Population III stars are believed to have formed roughly 200 million years after the Big Bang, within small dark-matter clumps, and to have been extremely massive and short-lived.
Visbal's team says LAP1-B meets all three predictions: it exists within a dark matter halo about 50 million times the Sun's mass, its stars range from 10 to 1,000 solar masses, and they form compact clusters, just a few thousand solar masses in total.
Spectral readings of the surrounding gas also show almost no metal content, suggesting the system is young enough that only a few of its earliest stars have exploded as supernovae, enriching the gas with early elements.
The tip of the iceberg
Researchers caution that the finding is not yet definitive proof of Population III stars. Uncertainties remain about the amount of material ejected by early supernovae and the accuracy of current cosmological models.
Still, the discovery marks a breakthrough in the search for the universe's earliest light. The team believes that gravitational lensing, combined with JWST's capabilities, will soon reveal more such systems.
"LAP1-B may only represent the tip of the iceberg in the study of Population III stars," the researchers conclude.