Hubble study finds most of the expected oxygen missing from 37 nearby dwarf galaxies

2 November 2026

A study using the Hubble Space Telescope has found that much of the oxygen expected in 37 nearby dwarf galaxies is simply not there.
Computer models predict far more oxygen than the galaxies actually hold, and the researchers say dwarf galaxies keep only a small part of what their stars produce.
The likely explanation is galactic winds driven by exploding stars, which appear to strip oxygen out of low mass galaxies more effectively than current models allow.
The 37 galaxies were chosen because their masses fall in the range where models predict rising oxygen loss, and because they are close enough for the telescope to pick out individual stars.
The work is part of the Galaxies Losing Oxygen via Winds project, abbreviated GLOW, and has been published in The Astrophysical Journal.
Along with archival Hubble images the team used data from the retired Spitzer Space Telescope, the Very Large Array and the Australian Telescope Compact Array.
Oxygen matters because it is the most abundant element after hydrogen and helium and is easy to measure, so it traces how heavy elements spread through and out of galaxies.
It is still not clear whether the missing oxygen sits in the gas around these galaxies or has been thrown out altogether.