Overview
- A Nature Astronomy paper, published Aug. 18, 2026, reports that high-quality JWST infrared spectra combined with Very Large Telescope data reveal a large population of faint, low-mass stars in nine massive, quiescent galaxies.
- For one galaxy that formed less than 1.5 billion years after the Big Bang the extra low-mass stars raise the inferred stellar mass by as much as four times compared with earlier estimates.
- The team infers a 'bottom-heavy' initial mass function, meaning these systems formed many more small stars relative to big stars than the standard, near-universal IMF assumption predicts.
- Researchers detected the faint-star signatures by modeling subtle absorption features in the infrared spectra and plan to apply the same method to earlier, higher-redshift galaxies to test how common the effect is.
- If confirmed more broadly, the result will force revisions to models of early galaxy growth, raise estimates of the total stellar mass in the young universe, and imply a higher potential for early planet formation because low-mass stars commonly host planets.