Hidden faint stars make ancient galaxies far heavier than estimated

Using JWST and ground-based data, astronomers studied nine massive, mature galaxies from the early universe and discovered they contain many more small, faint stars than previously assumed. This hidden population could make these galaxies three to four times more massive than earlier estimates, complicating theories of galaxy formation. The findings also hint that planets around low-mass stars may have been more common in the early cosmos.