Webb Finds Early Galaxies Up to 4 Times More Massive as Hidden Stars Rewrite Models
Updated
Updated · Gizmodo · Aug 24
Webb Finds Early Galaxies Up to 4 Times More Massive as Hidden Stars Rewrite Models
3 articles · Updated · Gizmodo · Aug 24
Summary
Nine ancient galaxies analyzed with Webb spectra and Very Large Telescope data appear significantly heavier than earlier estimates because they contain many more faint, low-mass stars than visible light alone suggested.
One galaxy formed less than 1.5 billion years after the Big Bang may be four times more massive than previously believed, with bright stars having masked a much larger underlying stellar population.
The Nature Astronomy study challenges the long-held assumption that stars form in similar proportions across the universe, indicating the most massive early galaxies were unusually rich in low-mass stars.
Those results deepen a broader Webb-era puzzle: galaxies had already grown huge within about 500 million years of the Big Bang, forcing revisions to models of early galaxy formation.
Researchers said the hidden mass could ripple beyond galaxy counts, potentially implying more planets formed in the early universe because low-mass stars are common planetary hosts.