Published: Tue, August 07, 2018
Sci-tech | By April Francis

Mysterious Rogue Planet Detected Outside Solar System

Mysterious Rogue Planet Detected Outside Solar System

The giant planet lies just 20 light-years from Earth and was spotted with the Very Large Array (VLA) telescope in New Mexico, thereby becoming the first planetary-mass object to ever be detected through radio telescopy, Science Alert reports.

Although this particular object was first picked up on in 2016, it was thought to be one of five recently discovered brown dwarfs.

They're calling it a "rogue" planet because it appears to be travelling through space without any kind of orbit around a parent star. The team's analysis showed the planet's magnetic field is around 200 times stronger than Jupiter's, and this could help explain why it also has a strong aurora.

In the first radio-telescope detection of a planetary-mass object beyond our solar system, astronomers have found the odd celestial body has 12.7 times the mass of Jupiter. The object is about twelve times as massive as Jupiter and has a surprisingly powerful magnetic field.

"This object is right at the boundary between a planet and a brown dwarf, or "failed star", and is giving us some surprises", Dr Melodie Kao and astronomer at Arizona State University told The Independent. Nicknamed "failed stars", brown dwarfs are larger than planets, but not quite large enough to fuse hydrogen, the way stars do.

The rogue extrasolar planetary-mass object's young age meant that it was in fact so much less massive that it could be free-floating planet - only 12.7 times more massive than Jupiter, with a radius 1.22 times that of Jupiter.

This Hubble telescope snapshot shows auroras on Jupiter
This Hubble telescope snapshot shows auroras on Jupiter

Further research however, saw that one of the objects, called SIMP J01365663+0933473, was considerably younger and smaller than the others.

Compared to the Sun's 5,500-degree-Celsius surface temperature (9,932 degrees Fahrenheit), it's relatively cool, coming in with a surface temperature of 825 degrees Celsius (around 1517 degrees Fahrenheit).

On Earth, auroras are generated by interactions between its magnetic field and solar winds.

"We think these mechanisms can work not only in brown dwarfs, but also in both gas giant and terrestrial planets".

Nevertheless, we still can't figure out how brown dwarf stars get auroras, considering they're nowhere near any type of stellar winds. One rule of thumb in drawing the distinction is the mass below which fusion of deuterium is not possible - about 13 Jupiter masses. It is a component of the National Radio Astronomy Observatory (NRAO).

"Such a strong magnetic field presents huge challenges to our understanding of the dynamo mechanism that produces the magnetic fields in brown dwarfs and exoplanets and helps drive the auroras we see", said Caltech astronomer Gregg Hallinan.

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