For years, astronomers have been looking for the first generation of stars, primordial remnants of the early universe. And they may have just discovered them.
Researcher Ari Visbal of the University of Toledo, Ohio, and colleagues believe they have discovered so-called Population III (Pop III) stars after conducting an exhaustive review of earlier James Webb Space Telescope (JWST) images of a faraway galaxy called LAP1-B.
These are believed to have formed roughly 200 million years after the Big Bang, deep in the so-called “cosmic dawn”.
Pop III stars are theorised to consist almost entirely of hydrogen and helium (with trace lithium), since they formed before heavier elements existed in significant quantities.
The discovered system appears to match three major properties of such stars:
They emerged in a dark-matter “halo” of approximately 50 million times the Sun’s mass
The stars are extremely massive (in the range of 10-1,000 solar masses)
They cluster in small groups totalling a few thousand solar masses
Further evidence comes from the surrounding gas in LAP1-B, which shows only trace amounts of “metals” (elements heavier than helium), implying that the stars are truly primordial and that some of the earliest supernovae may already have enriched the gas.
The researchers emphasise that while this is a compelling candidate, it is not yet fully confirmed as a Pop III system, as uncertainties remain in modelling early-universe physics and in how much material the first supernovae ejected.
They suggest the use of gravitational-lensing techniques in combination with the James Webb Space Telescope could help find further examples and deepen understanding of the first stars.