Massive rogue planet found lurking outside our solar system

Researchers have discovered a "rogue" planet outside of our solar system using the Very Large Array (VLA), the first time such a discovery has been made using a radio telescope. The planet is called rogue due to its lack of a parent star, having the distinction of being something between a planet and a brown dwarf, which is an object that has too great of a mass to be called a planet.

The newly discovered object, which is called SIMP J01365663+0933473, is estimated to have a mass approximately 12.7 times greater than Jupiter and a magnetic field more than 200 times stronger than Jupiter's own magnetic field. Astronomers say the rogue planet is located 20 light-years from Earth and is about 200 million years old — which, in the grand scheme of things, is considered young for a planet.

Though not as hot as our Sun, this newly discovered object is quite toasty at about 1,500 degree Fahrenheit. The rogue body is nearly large enough to be considered a gas giant planet and it offers researchers the opportunity to study these massive objects, shedding light on their magnetic realities.

Of particular note is the presence of strong auroras, which typically involve a planet's magnetic field interacting with solar wind. Researchers aren't sure how brown dwarf auroras happen — "rogue" planets like these lack a nearby star's solar wind for the magnetic field to interact with. However, a nearby moon or another orbiting planet may be the answer.

"This object is right at the boundary between a planet and a brown dwarf, or 'failed star,' and is giving us some surprises that can potentially help us understand magnetic processes on both stars and planets," said study lead Melodie Kao. SIMP J01365663+0933473 was first detected in 2016.


National Radio Astronomy Observatory