Overview
- An international team reported a gas‑giant object of at least about 0.9 times Jupiter's mass orbiting the brown dwarf CD‑35 2722 B, with a roughly 170‑day period in a system about 71–73 light years away.
- The signal came from high‑precision radial‑velocity measurements made with the CRIRES+ spectrograph on ESO's Very Large Telescope, marking the first time this technique has produced evidence for a satellite around a brown dwarf.
- Authors provisionally call the companion an “exosatélite” because it is planet‑mass but orbits a substellar brown dwarf that itself orbits a roughly 0.5‑solar‑mass star, a hierarchy that blurs the line between planets and moons.
- Researchers say follow‑up observations are needed to confirm the object's mass and orbit and to test formation ideas, and they expect next‑generation telescopes such as the Extremely Large Telescope to be able to refine or overturn the result.
- The team frames this as the strongest evidence so far for a natural satellite beyond the Solar System and says the finding prompts competing origin scenarios—formation in a disk, gravitational capture, or later dynamical evolution—that will inform models of substellar systems.