News by Levels · Level 3 · Student worksheet

Hubble Survey Reveals an Oxygen Puzzle in Dwarf Galaxies

Name: __________________________ Date: __________________

Read the story

A survey of 37 nearby dwarf galaxies has revealed a substantial gap between the oxygen they contain and the amount scientists expected their stars to have produced. The study appeared in The Astrophysical Journal on November 2.

Researchers combined archival Hubble images with observations from other telescopes to trace oxygen in stars and gas and reconstruct the galaxies’ histories. Oxygen is a useful indicator of how heavier elements are distributed.

The team says winds powered by massive stars and supernova explosions appear more effective at removing material from low-mass galaxies than current models suggest. This may help explain the missing oxygen.

The result does not establish its final location. Scientists still need to determine how much remains in diffuse gas around the galaxies and how much has travelled beyond their surroundings.

Source: NASA, 2026-11-02. https://science.nasa.gov/missions/hubble/nasas-hubble-uncovers-case-of-missing-oxygen-in-nearby-dwarf-galaxies/

Read and practise

1. What discrepancy did the survey of 37 dwarf galaxies find?

   1. They contained less oxygen than their stars were expected to have produced.
   2. They contained more oxygen than their stars were expected to have produced.
   3. Their oxygen matched the expected amount exactly.

2. How did researchers investigate the galaxies?

   1. They used only new Hubble images without other observations.
   2. They reconstructed the histories using only ground-based telescopes.
   3. They combined archival Hubble images with observations from other telescopes.

3. What question about the missing oxygen remains open?

   1. How many galaxies were included in the survey
   2. How much is in surrounding gas and how much has travelled beyond it
   3. Whether any oxygen is produced by stars

Your turn

Explain the proposed role of galactic winds and what the study has not established.

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Read online: https://newsbylevels.com/news/hubble-missing-oxygen-dwarf-galaxies-glow-study-2026/level-3/