# Small Galaxies Expel Most Oxygen Produced by Their Stars New Hubble telescope research reveals dwarf galaxies struggle to retain essential life-sustaining elements. - **Source:** [Mashable](https://mashable.com) - **Published:** 2026-11-08 - **Topic:** [science](https://brifing.si/c/science) - **Original article:** - **On Brifing:** https://brifing.si/s/2487b549-5440-42fe-9542-ae37796bb3b8 ## Oxygen Loss in Dwarf Galaxies New research using the Hubble Space Telescope reveals that small galaxies retain only a fraction of the oxygen their stars produce. While larger galaxies hold onto significantly more, dwarf galaxies keep an average of just 11 percent. Some of the least efficient galaxies in the study retained as little as 4 percent. ## Supernova Winds Drive Expulsion The primary mechanism for this loss is the explosive death of massive stars, known as supernovas. These events generate powerful winds capable of pushing gas entirely out of a galaxy. Because dwarf galaxies possess relatively weak gravitational pull, they struggle to contain this material, allowing the oxygen to escape into surrounding space. ## Tracking Oxygen via GLOW Project The Galaxies Losing Oxygen via Winds project, or GLOW, tracks oxygen to understand how galaxies recycle matter. Oxygen serves as an ideal tracer because it is the most abundant element after hydrogen and helium. Researchers can measure it easily, providing a clear window into the lifecycle of matter within these cosmic structures. ## Methodology and Star History To calculate oxygen levels, the team used high-resolution Hubble images to identify individual stars within 37 nearby dwarf galaxies. By analyzing the history of star formation, scientists determined how much oxygen each galaxy should have produced. They then compared these theoretical totals against the actual amounts of oxygen remaining in the gas. ## Environmental Influence on Retention Location plays a critical role in how much oxygen a galaxy retains. Galaxies situated in crowded areas or within 3 million light-years of a larger neighbor tend to keep more oxygen. This suggests that surrounding gas may push expelled oxygen back into the galaxy or allow it to scoop up material from neighbors. ## The Mystery of Missing Oxygen Despite tracking oxygen in stars and gas, the final destination of the expelled material remains unknown. Earlier studies found only 1 to 7 percent of the missing oxygen in the hot gas halos surrounding galaxies. Even when accounting for cooler gas, these halos likely hold at most one-third of the total produced oxygen. ## Intergalactic Seeding Potential Scientists suspect that much of the missing oxygen escapes into intergalactic space, potentially seeding the vast voids between galaxies. If this hypothesis is correct, the universe's smallest galaxies may act as the primary spreaders of oxygen. This process would distribute the essential element across the cosmos, far beyond the galaxies' own boundaries. ## Future Research and Observations Researchers plan to expand their investigation using the Nancy Grace Roman Space Telescope to identify even smaller, fainter galaxies. Additionally, the team will utilize the James Webb Space Telescope to study stars in greater detail. These future observations aim to confirm if the missing oxygen is indeed escaping into the deep intergalactic medium. ## Sources covering this story - https://mashable.com/science/hubble-telescope-dwarf-galaxies-missing-oxygen — --- _Summary written by Brifing from the original reporting. Copyright in the original article belongs to its publisher; read the full piece at the link above._