Interacting Galaxies
Example: Arp 273
Two or more galaxies close enough to pull each other out of shape, sometimes on their way to merging.
Key facts
- What it is
- Galaxies pulling on each other by gravity
- Can lead to
- Mergers and new star formation
- Example shown
- Arp 273
- Example’s distance
- About 300 million light-years
About the Interacting Galaxies
How to recognise it
When galaxies pass close together, their gravity distorts their shapes. Look for twisted arms, long tails of stars stretching into space, or bursts of new star formation. Over time, interacting galaxies can merge into a single, larger galaxy.
The example: Arp 273
Arp 273 is a pair of galaxies about 300 million light-years away in the constellation Andromeda. The larger galaxy’s arm has been twisted into a rose-like shape by its smaller companion below.
Sources
Facts checked: 29 October 2026
