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James Webb Telescope Data Reveal Pristine Gas Clump 450 Million Years After Big Bang
Data from the James Webb Space Telescope show a bright clump of pristine gas, potentially housing first-generation stars, just 450 million years after the Big Bang. The clump, dubbed Hebe, lacks elements heavier than helium and emits light from highly energized helium and hydrogen. Science News reported the findings in three papers submitted to arXiv.org on March 20.
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A bright clump of pristine gas, irradiated by energetic light and potentially housing primordial stars, has been identified 450 million years after the Big Bang, according to data from the James Webb Space Telescope. Science News reported that the clump displays chemical hallmarks of first-generation stars, including no elements heavier than helium.
The identification marks a new candidate for these population III stars, pushing evidence for such pristine stars earlier than previous findings, which dated to around 1 billion years after the universe's start.
The clump, dubbed Hebe, was first spotted in 2024, with higher resolution observations taken by the James Webb Space Telescope in 2025. In an image showing light from a highly energized form of helium, the gas in Hebe glows brightly, credited to R. org 2026, JWST/NASA, ESA and CSA.
Hebe sits near a galaxy named GN-z11, which is not visible in this light, and GN-z11 has the mass of 1 billion suns. Astronomers look for evidence of elements heavier than helium to determine if a candidate is a first-generation star. Hebe showed no such evidence, emitting light specific to highly energized helium and hydrogen, indicating it contains an object or objects that emit extremely high-energy radiation.
The team estimates Hebe is up to 1,200 light-years across, contains two distinct clusters, and holds the mass of between 10,000 and several hundred thousand suns. First-generation stars, known as population III stars, would have been massive, up to 1,000 times the mass of the sun, and born with only hydrogen, helium, and a tiny amount of lithium. 5 billion years ago.
