Science

Early galaxies may be up to four times more massive than previously estimated, study finds

New telescope observations reveal populations of faint, low-mass stars concealed within massive ancient galaxies.

Updated Aug 24, 2026 · 00:33 UTC1 reports

The short version

Astronomers analyzing James Webb Space Telescope and Very Large Telescope data found that massive early galaxies host far more faint, low-mass stars than expected.
The presence of these hidden stars means some early galaxies could have up to three to four times more mass than previously calculated.
The discovery challenges conventional models of early galaxy evolution and raises questions about how such large stellar populations formed shortly after the Big Bang.

An international research team examined nine massive, mature early galaxies using combined data from the James Webb Space Telescope and the ground-based Very Large Telescope.[ScienceDaily]
Spectral analysis revealed a larger proportion of low-mass, faint stars hidden by bright, luminous stars compared to proportions found in galaxies like the Milky Way.[ScienceDaily]
One studied galaxy that formed within 1.5 billion years of the Big Bang was estimated to be up to four times more massive than prior calculations suggested.[ScienceDaily]
The findings, published in Nature Astronomy, challenge the assumption that stars formed in uniform proportions throughout cosmic history.[ScienceDaily]

Current astrophysical models have not yet resolved the theoretical mechanism explaining how such large quantities of low-mass stars could assemble so rapidly following the Big Bang.[ScienceDaily]
Researchers note that whether this star-formation pattern extends to even earlier cosmic periods remains unconfirmed pending future observations.[ScienceDaily]