Astronomers utilizing the NASA/ESA/CSA James Webb House Telescope have detected methane emission from CWISEP J193518.59-154620.3 (W1935 for brief), an remoted brown dwarf with a temperature of roughly 482 Okay. Their findings additionally counsel that W1935 would possibly generate aurorae much like these seen on our personal planet in addition to on Jupiter and Saturn.
An artist’s impression of the brown dwarf W1935. Picture credit score: NASA / ESA / CSA / L. Hustak, STScI.
W1935 is situated round 47 light-years away within the constellation of Sagittarius.
The brown dwarf was co-discovered by Yard Worlds: Planet 9 citizen science volunteer Dan Caselden and NASA’s CatWISE crew.
The mass for W1935 isn’t well-known but it surely possible ranges between 6 and 35 occasions the mass of Jupiter.
After quite a lot of brown dwarfs noticed with Webb, Dr. Jackie Faherty from the American Museum of Pure Historical past and colleagues observed that W1935 regarded comparable however with one putting exception: it was emitting methane, one thing that’s by no means been seen earlier than on a brown dwarf.
“Methane fuel is anticipated in big planets and brown dwarfs however we normally see it absorbing mild, not glowing,” Dr. Faherty mentioned.
“We have been confused about what we have been seeing at first however finally that remodeled into pure pleasure on the discovery.”
Laptop modeling yielded one other shock: W1935 possible has a temperature inversion, a phenomenon through which the environment will get hotter with rising altitude.
Temperature inversions can simply occur to planets orbiting stars, however the brown dwarf is remoted, with no apparent exterior warmth supply.
“We have been pleasantly shocked when the mannequin clearly predicted a temperature inversion,” mentioned Dr. Ben Burningham, an astronomer on the College of Hertfordshire.
“However we additionally had to determine the place that further higher environment warmth was coming from.”
To analyze, the astronomers turned to our Photo voltaic System. Particularly, they checked out research of Jupiter and Saturn, which each present methane emission and have temperature inversions.
The possible trigger for this function on photo voltaic system giants is aurorae, subsequently, the researchers surmised that that they had uncovered that very same phenomenon on W1935.
Planetary scientists know that one of many main drivers of aurorae on Jupiter and Saturn are high-energy particles from the Solar that work together with the planets’ magnetic fields and atmospheres, heating the higher layers.
That is additionally the rationale for the aurorae that we see on Earth, generally known as the northern or southern lights since they’re most extraordinary close to the poles.
However with no host star for W1935, a photo voltaic wind can not contribute to the reason.
There may be an attractive further motive for the aurora in our Photo voltaic System.
Each Jupiter and Saturn have lively moons that often eject materials into house, work together with the planets, and improve the auroral footprint on these worlds.
Jupiter’s moon Io is essentially the most volcanically lively world within the Photo voltaic System, spewing lava fountains dozens of miles excessive, and Saturn’s moon Enceleadus ejects water vapor from its geysers that concurrently freezes and boils when it hits house.
Extra observations are wanted, however the researchers speculate that one rationalization for the aurora on W1935 is perhaps an lively, yet-to-be found moon.
“Each time an astronomer factors Webb at an object, there’s an opportunity of a brand new mind-blowing discovery,” Dr. Faherty mentioned.
“Methane emission was not on my radar once we began this challenge however now that we all know it may be there and the reason for it so engaging I’m continuously on the look-out for it. That’s a part of how science strikes ahead.”
A paper on the findings was printed within the journal Nature.
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J.Okay. Faherty et al. 2024. Methane emission from a cool brown dwarf. Nature 628, 511-514; doi: 10.1038/s41586-024-07190-w
