Evidence of a Possible Moon Orbiting a Brown Dwarf in a Distant Stellar System
Astronomers detected signals indicating a possible body orbiting a brown dwarf in a system with a star of about half the Sun’s mass; the body's mass approaches Jupiter’s and its orbital period is estimated at about 170 days.
Researchers reported detecting signs that point to a possible moon orbiting a brown dwarf outside the Solar System, and if the data are confirmed this could represent the first evidence of its kind, according to scientific reports.
The system under study consists of a star with a mass of about half the Sun’s mass, around which a brown dwarf of roughly 37 times Jupiter’s mass orbits. The researchers observed indications of an additional object near the brown dwarf with an estimated mass of no less than 90% of Jupiter’s mass, and it could complete an orbit around the brown dwarf in about 170 days.
The object was not observed directly; the team relied on a spectrograph at the European Southern Observatory in Chile, using the radial velocity technique to measure slight oscillations in the motion of the bodies caused by the gravitational influence of nearby objects.
The researchers noted that the object’s mass is close to that of a planet, but it differs from known planets in that it orbits a brown dwarf which itself orbits a star. So far there is no agreed scientific definition for this class of moons outside the Solar System, and further observations and verification are still needed before the discovery can be considered confirmed.
