Hubble Telescope Discovers a Pair of Small Dwarf Galaxies With Many Interesting Features

A new image from the Hubble Space Telescope shows a small dwarf galaxy called IC 3430, located 45 million light-years away. The galaxy is classified as a dwarf because of its small size and elliptical appearance.

These are smooth and featureless elliptical galaxies that appear as a diffuse point of light. They are completely different from spiral galaxies, like our own Milky Way, which have a distinct structure consisting of a central axis and elongated spiral arms.

In this image, the smooth oval shape of IC 3430 is clearly visible. Elliptical galaxies are mostly composed of old stars, as they lack the gas needed to form new stars. However, in the case of IC 3430, a core of hot blue stars can be seen at the center of the galaxy. These hot stars are young, which is rare for elliptical galaxies.

Not long ago, the Hubble Space Telescope also sent back another image showing a dwarf galaxy, called NGC 5238. This galaxy is located 14.5 million light years away from Earth, but has a different and more complex structure than normal dwarf galaxies. It contains unusual bright spots that stand out quite prominently. These are groups of stars called globular clusters.

The structure of this galaxy provides clues to its history. Astronomers think the structure stems from a historical merger, when another galaxy passed too close to this one and the two galaxies merged into one. Such a process causes pockets of stars to form as gravitational disturbances push and pull on the gas.

Signs of a historical merger include clusters of stars within a galaxy that have different chemical properties, suggesting they formed in a different environment than neighboring galaxies. By studying smaller galaxies like IC 3430, astronomers can build their understanding of how galaxies form and merge.