Rare Quadruple Star System Discovered in the Milky Way

In August 2025, an international team of scientists reported the discovery of an extremely rare quadruple star system in the Milky Way.

The system, named UPM J1040−3551 AabBab, features a pair of cold brown dwarfs orbiting a pair of young red dwarf stars — a configuration never observed before.

Key Points

Brown Dwarfs Explained: Brown dwarfs are “failed stars” — celestial objects that form like stars but lack the mass to sustain hydrogen fusion.
Detection Challenges: Brown dwarfs are faint and cold, making them difficult to observe directly.
Significance of Discovery: This is the first known quadruple system containing two T-type brown dwarfs orbiting two young red dwarfs.
Brown dwarfs help scientists understand the boundary between stars and planets, offering insights into star and planet formation conditions, as well as the distribution of mass in the universe — a key factor in studying dark matter.