Otherworldly lights: Aurora million times brighter than on Earth found outside Solar System
The scintillating phenomenon was observed using the National Radio Astronomy Observatory in New Mexico and the Hale telescope in San Diego.
What researchers saw were beautiful red, green and orange streaks rising above the north face of LSR J1835+3259 – the brown dwarf in the constellation Lyra. The research is published in the journal Nature.
The brown dwarf is about the size of Jupiter, but has 80 times the mass.
Auroras, which are the result of charged particles coming from the star interacting with a planet's atmosphere, have been previously seen around all the planets in our solar system. This is the first time the event was recorded outside it – and also the brightest aurora ever seen.
“If you could stand there and look upwards, the aurora would appear one million times brighter than the northern lights,” Stuart Littlefair at University of Sheffield, who was part of the study, told The Guardian.
But what the scientists found especially important about the discovery is that it answers some rather long-standing questions, one of which could shake up our entire understanding of brown dwarfs. For years, Earth’s scientists couldn’t figure out why the things appeared to brighten at certain times and dim at others.
They now have a strong basis for believing this is due to the glow of the auroras, visible only at certain angles and at regular intervals.
The discovery also shed light on a very important detail about brown dwarfs – bodies we have traditionally come to know as failed suns. At its heart, it’s a giant ball of hot gas which straddles the category between star and planet. They can’t muster up enough internal heat in order to become a sun, so are replaced by a cool mass.
But the aurora now witnessed on LSR J1835+3259’s surface challenges this view, asking the viewer to consider that, maybe, we were dealing with failed planets. “They have cool atmospheres with clouds in, just like Jupiter, and now we see they have auroras, too,” Littlefair says.
“It’s more evidence we should think of them as scaled-up planets more than scaled-down stars.”