For a long time Earth’s Northern Lights have been as mysterious as they are beautiful. Now, as scientists are learning more about auroras, the dazzling phenomenon that cause effects like the Northern Lights, they have discovered that the effect is not restricted to planets, but can be seen on a distant brown dwarf star. In fact, the aurora that occurs on this so-called ‘failed star’ is nearly 10,000 times stronger than those seen elsewhere in space.
According to a paper published on July 29 in the journal Nature, the brown dwarf star called LSR J1835+3259, which resides 18 light years away from Earth, has demonstrated signs of what could be a super powered aurora. The discovery sheds light on just how little we know about brown dwarfs, which hold an awkward classification of being not quite stars but not really planets either.
Brown dwarfs are often more massive than planets like Jupiter, but still smaller than your average star. Despite their size, brown dwarfs are quite difficult to detect, which has made studying them harder. However, a team of international scientists studying LSR J1835, with a combination of the most powerful radio telescope in the world and a series of optical telescopes, detected that the planet emitted regular sharp radio pulses at the same time as it displayed an optical phenomenon. If the effect turns out to be an aurora, it would be just another reason why the ‘star’ moniker might not quite fit the brown dwarf.
“Brown dwarfs span the gap between stars and planets and these results are yet more evidence that we need to think of brown dwarfs as beefed-up planets, rather than ‘failed stars,’” said Dr Stuart Littlefair, from the University of Sheffield’s Department of Physics and Astronomy in a report by Eureka Alert. “We already know that brown dwarfs have cloudy atmospheres – like planets – although the clouds in brown dwarfs are made of minerals that form rocks on Earth now we know brown dwarfs host powerful auroras too.”
This is not the first time an aurora has been seen on other planets. In fact, Jupiter is known to display rather vibrant auroras. Scientists know that an auroral display is the result of charged particles, commonly from the sun, entering a planet’s magnetic field where they are accelerated until they collide with gas atoms causing a dazzling visual effect.
But particles from the sun aren’t necessary for auroras to exist; Jupiter’s auroras are caused by particles that come from the planet’s many moons. The Washington Post reported that, like Jupiter, brown dwarfs might get their auroras from particles cast off by nearby planets or some other more mysterious source. For now, this discovery has caused many astronomers and scientists to take a step back and reevaluate how we describe the universe. As our understanding of both auroras and brown dwarf stars increases we may have to start looking for a new term for the ‘failed stars.’