JWST Finds 9 Early Galaxies Hold More Mass, With 1 Up to 4 Times Heavier
Updated
Updated · Space.com · Aug 20
JWST Finds 9 Early Galaxies Hold More Mass, With 1 Up to 4 Times Heavier
3 articles · Updated · Space.com · Aug 20
Summary
Nine early galaxies studied with JWST and the Very Large Telescope contain far more faint, low-mass stars than expected, pushing their estimated masses well above earlier calculations.
JWST’s sensitivity and high-quality spectra let astronomers isolate the subtle signatures of small stars that had been drowned out by brighter, massive stars in galaxy-wide light measurements.
One galaxy formed less than 1.5 billion years after the Big Bang appears up to four times more massive than previously thought because of its unusually large population of small stars.
The result challenges the long-held assumption that galaxies across cosmic history formed stars in roughly the same mass proportions, implying galaxy-formation models may need revision.
Researchers said the hidden mass in small stars could also mean more planets formed in the early universe, and they plan to apply the method to even earlier galaxies.