A group of scientists recently discovered the faintest and lowest-mass Milky Way satellite ever observed, located approximately 30,000 light-years away.

This stellar collection, named Ursa Major III / UNIONS 1 (UMa3/U1), consists of around 60 stars, estimated to be around 10 billion years old, within a space spanning about 10 light-years.

Despite its small size and low luminosity, the stars in UMa3/U1 are gravitationally bound together, either forming a dwarf galaxy or a star cluster.

Using the Keck Observatory’s Deep Imaging Multi-Object Spectrograph, researchers confirmed that the stars share similar velocities and chemistries, indicating their cohesion.

UMa3/U1’s discovery challenges current understandings of galaxy formation and raises questions about the definition of a galaxy, Gizmodo reported.

The system may be dominated by dark matter, inferred from the spread of velocities among its stars.

Dark matter, although its nature remains unknown, likely acts as a gravitational force holding the stars together.

Further observations may provide insights into the true nature of UMa3/U1 and the role of dark matter in its formation.

Written by B.C. Begley