NGC 4449, a dwarf galaxy captured by the Hubble Space Telescope, contains only a few billion stars and measures about one-tenth the size of the Milky Way. Dwarf galaxies like NGC 4449 are the most common type of galaxy in the universe.
Observations reveal that NGC 4449 and similar dwarf galaxies contain less oxygen than current models predict. Their stellar winds and supernovae appear remarkably effective at ejecting oxygen and other heavy elements into space. These tiny galaxies may play an outsized role in distributing heavy elements, the building blocks of stars, planets, and life, throughout the universe.