To confirm that the observed signal was indeed caused by a moon, the research team also examined other possible factors. These included apparent periods resulting from errors in corrections for Earth’s orbital motion, seasonal variations in atmospheric conditions, and the effects of the brown dwarf’s own rotation. An artist’s concept of a moonlike object (center) orbiting the brown dwarf CD-35 2722 B (right). Researchers refer to this object as an “exosatellite” and describe it as a massive gas giant with a mass at least equal to that of Jupiter. Video: ESO/M. Kornmesser Furthermore, calculations of the Roche limit—the boundary beyond which a satellite would be torn apart by the brown dwarf’s tidal forces—and the Hill radius—the radius of the brown dwarf’s gravitational influence—confirmed that the satellite’s orbit falls within a range where it can exist in a physically stable manner. According to the researchers, this is the first evidence of a satellite orbiting a brown dwarf companion obtained using this method. A few months earlier, another team had gathered clues suggesting the presence of a …