Ursa Major III May Be a Star Cluster, Not a Dark-Matter Dwarf Galaxy
Astronomers have long thought Ursa Major III, also called UNIONS 1, was a dark-matter-packed dwarf galaxy. But new simulations suggest it may instead be a compact star cluster bound by black holes and neutron stars. Located 30,000 light-years away, Ursa Major III contains just ~60 visible stars yet shows puzzlingly high stellar velocities. The new analysis explains this without invoking dark matter, challenging assumptions about tiny galaxies. If correct, it reduces the Milky Way’s dwarf count and may reveal an entirely new class of faint stellar systems.
