First exomoon candidate discovered orbiting brown dwarf in CD‑35 2722 system

Astronomers announced on 22 July 2026 that they have likely identified the first exomoon – a natural satellite outside the Solar System – in the CD‑35 2722 system, located about 70 light‑years from Earth. Using the European Southern Observatory’s Very Large Telescope in Chile, the team detected a Jupiter‑mass object through the radial‑velocity wobble it induces on a brown dwarf (CD‑35 2722 B) that itself orbits a red dwarf star of roughly half the Sun’s mass.

The discovery, led by Kevin Hoy of the University Diego Portales and involving researchers such as Alice Zurlo, was published in Nature. Because the object orbits a brown dwarf rather than a planet, the researchers are debating its classification, using provisional terms like “exosatellite”, “exomoon” or “exoluna”. The finding challenges conventional definitions of planets and moons and opens new questions about the formation and diversity of satellite systems beyond our own.

The result marks a milestone after more than four decades of searches for moons around exoplanets, and it highlights the capabilities of modern high‑precision spectroscopy for detecting faint companions in distant planetary systems.