Astronomers have unveiled a remarkable discovery in the Milky Way galaxy: a circumbinary planet orbiting two brown dwarfs. Unlike the more commonly known circumbinary planets, which orbit two stars, this newly identified planet is bound to two celestial objects that are neither full-fledged stars nor typical planets. Brown dwarfs, sometimes referred to as “failed stars,” are objects that did not accumulate enough mass to initiate nuclear fusion like stars but are more massive than the largest planets.
Utilizing the European Southern Observatory’s Very Large Telescope located in Chile, researchers detected this distant planet approximately 120 light-years away from Earth. The planet is believed to be a gas giant, with a mass estimated to be four or five times greater than that of Earth. Its host, the two brown dwarfs, are each about 35 times the mass of Jupiter and are gravitationally bound, orbiting one another closely, at merely four percent of the distance between Earth and the sun. The planet, designated as 2M1510 (AB) b, maintains an orbit around these two brown dwarfs.
Interestingly, the planetary system also includes another brown dwarf, located about 250 times the distance between Earth and the sun from the central pair, but its gravitational influence is negligible. Among the approximately 5,800 exoplanets confirmed beyond our solar system, only 16 have been identified as circumbinary, and this discovery marks the first instance of a planet orbiting brown dwarfs rather than stars.
The orbit of this planet is notably distinctive, as it does not align with the orbital plane of the brown dwarfs. Instead, it follows a polar orbit, nearly perpendicular to the plane, completing a journey in at least 100 days. This polar orbit is uncommon, as no planet within our solar system exhibits such a trajectory. The few known exoplanets with polar orbits typically revolve around a single star.
In a binary system, like the one found in this research, two celestial bodies orbit each other, reminiscent of the fictional setting in the “Star Wars” films. An observer on this planet would witness a view unlike the iconic scene of Tatooine’s twin suns. Both brown dwarfs would appear identical and red, emitting significantly less light than our sun.
Each of these brown dwarfs has a mass about four percent that of the sun and a luminosity of just 0.1 percent. This unusual planetary configuration offers a fascinating glimpse into the diversity of planetary systems. Such discoveries challenge preconceived notions and provide new opportunities for learning and exploration in the field of astronomy.