Astronomers Spot Potential Moon Orbiting a Brown Dwarf in Distant Star System
Researchers using ESO's VLT have found evidence of a massive satellite, at least Jupiter-sized, circling a brown dwarf that itself orbits the star CD-35 2722.
A study published in Nature reports the first plausible detection of an exosatellite beyond the Solar System. Using the CRIRES+ instrument on ESO's Very Large Telescope, Kevin Hoy and collaborators measured subtle radial-velocity shifts in a brown dwarf that orbits the star CD-35 2722, revealing a massive companion at least as heavy as Jupiter. The brown dwarf itself is more than 30 Jupiter masses, placing the satellite in a regime that challenges conventional definitions of moons and planets.
Co-author Alice Zurlo noted that the system's architecture—star, brown dwarf, then a giant satellite—does not fit Solar-System-based terminology. If confirmed, the finding could reshape how astronomers classify distant celestial objects and guide future searches with upcoming facilities like the ELT. The research underscores the potential diversity of planetary systems and the need for new classification frameworks.
Why it matters
It could redefine how scientists categorize moons and planets in other star systems.
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