Brown dwarf, dazzling aurora

[Hils]

"The sky above a failed star in a distant constellation shimmers with a
beautiful green and yellow aurora one million times brighter than the
northern lights. The spectacular light show is the first confirmed
aurora on a body outside the solar system, and the most powerful ever
recorded."

http://www.theguardian.com/science/2015/jul/29/astronomers-find-aurora-a-million-times-brighter-than-the-northern-lights

But this otherwise fine article doesn't describe how the auroras are formed!

[JAB]

On Wed, 29 Jul 2015 20:20:10 +0100, Hils <hi...@saynotospam.net> wrote:

>fine article

Source:

http://www.caltech.edu/news/failed-stars-host-powerful-auroral-displays-47428

[Martin Brown]

Somewhat like on Earth the magnetic axis of the brown dwarf and its spin
axis are not precisely aligned so that the auroral circle around the
magnetic pole is rotating in and out of our view.

The 18th magnitude object has its own Wiki entry

https://en.wikipedia.org/wiki/LSR_J1835%2B3259

(beyond the reach of all but the largest amateur scopes)

Think of it as a low budget and much less energetic pulsar or a Jupiter
on steroids and you will not be too far out. Where the electrons come
from that power the aurora is still unknown but stellar motion and/or
orbiting planets would be the most obvious candidates.

--
Regards,
Martin Brown

[Hils]

Excellent, thanks.

"In the case of brown dwarfs, charged particles cannot be driven into
their magnetosphere by a stellar wind, as there is no stellar wind to do
so. Hallinan says that some other source, such as an orbiting planet
moving through the brown dwarf's magnetosphere, may be generating a
current and producing the auroras. "But until we map the aurora
accurately, we won't be able to say where it's coming from," he says."

Wouldn't an "orbiting planet" have itself to be something like a gas
giant to produce the charged particles?