Overview
- The research team published results in Nature on 22–23 July reporting a gaseous object of at least 0.9 Jupiter masses orbiting the brown dwarf CD-35 2722 B with a roughly 170-day period based on VLT/CRIRES+ data.
- Researchers used high-precision radial-velocity measurements from the VLT spectrograph CRIRES+ to detect small oscillations in the brown dwarf caused by the companion, marking the first time this technique has delivered evidence for a satellite around a substellar object.
- The system is hierarchical: a roughly 0.5-solar-mass star hosts a brown dwarf of more than 30 Jupiter masses, and the newly detected companion orbits that brown dwarf rather than the star.
- The team provisionally calls the object an “exosatellite” because its mass is planet-like but its orbit is moon-like, and they list formation scenarios that include in-situ formation from a circum-brown-dwarf disk, capture after independent formation, or chaotic dynamical evolution.
- Scientists say next-generation telescopes such as the Extremely Large Telescope will be needed to confirm the object's nature, test formation theories, and search for other similar satellites that could change how we classify planets and moons.