On Earth, we get aurorae when energetic particles from the Sun are captured by the magnetic field of the Earth. These collide with gas molecules in the atmosphere and create the northern lights at certain times of year, at certain times of day, in certain parts of the country, but never localized entirely within one’s kitchen. But methane emissions are commonly found in gas giants like Jupiter and Saturn, where the heating in the upper atmosphere that powers the emissions is linked to aurorae.
The team that discovered the aurorae in brown dwarf W1935 theorizes that the emission may be facilitated by an internal process in the brown dwarf similar to the atmospheric phenomena of Jupiter, or perhaps interactions between the dwarf with nearby moons or interstellar plasma. What makes the discovery puzzling is that brown dwarfs do not have a star, so there is no obvious source of heat to the upper atmosphere that can cause aurorae.
“With W1935, we now have a spectacular extension of a solar system phenomenon without any stellar irradiation to help in the explanation,” Faherty added. “With Webb, we can really ‘open the hood’ on the chemistry and unpack how similar or different the auroral process may be beyond our solar system.”
