In April 2025, an international team of astronomers announced the discovery of a unique exoplanet, 2M1510 (AB) b, orbiting a pair of brown dwarfs in a polar orbit. This marks the first confirmed instance of a circumbinary planet found in such an extreme orientation, challenging existing models of planetary formation.
The 2M1510 system, located approximately 120 light-years away in the constellation Libra, features two brown dwarfs that orbit each other every 21 days. The exoplanet, 2M1510 (AB) b, orbits this pair at a 90-degree angle, completing an orbit in roughly 100 days. The brown dwarfs are known as 2M1510 A and 2M1510 B, and the system also includes a third brown dwarf, 2M1510 C, which orbits at a much greater distance.
The discovery, led by Thomas A. Baycroft, a Ph.D. student at the University of Birmingham, utilized data from the European Southern Observatory's Very Large Telescope (VLT). The team observed unusual gravitational interactions, leading them to conclude that a planet in a polar orbit was the only explanation. This finding provides valuable insights into the diversity of exoplanetary systems and supports theoretical models suggesting that planet-forming discs around binaries can evolve into such extreme orbital arrangements.