JWST Finds HeII & H Emission from Hebe, Pop III Stars
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- JWST used its NIRSpec-IFU instrument to detect a faint doubly ionized helium emission line from the companion object Hebe, located three kiloparsecs from the early galaxy GN‑z11 at redshift z≈10.6.
- Roberto Maiolino's team confirmed the helium signal and resolved it into two distinct components, reinforcing the claim that the emission originates from Population III stars.
- Elka Rusta's independent study detected a hydrogen emission line at the same location, providing a second anchor for the identification of the source.
- Hebe showed no detectable metal lines in its spectrum, a hallmark of primordial, metal‑free stellar populations.
- Elka Rusta's modeling of the helium‑to‑hydrogen ratio suggests a top‑heavy mass distribution for the first stars, with most masses between roughly 10 and 100 solar masses.
- ArXiv hosted the two preprint papers in 2026, which together constitute the strongest observational evidence yet for Population III stars.
Why it matters: Astronomers gain a direct observational window into the early universe, enabling testing of theories about the first stars and their role in cosmic chemical enrichment. These findings also validate theoretical predictions of a top‑heavy mass distribution, giving modelers concrete data to refine simulations of early star formation.
