Details

Autor(en) / Beteiligte

• Faherty, Jacqueline K
• Burningham, Ben
• Gagné, Jonathan
• Suárez, Genaro
• Vos, Johanna M
• Alejandro Merchan, Sherelyn
• Morley, Caroline V
• Rowland, Melanie
• Lacy, Brianna
• Kiman, Rocio
• Caselden, Dan
• Kirkpatrick, J Davy
• Meisner, Aaron
• Schneider, Adam C
• Kuchner, Marc Jason
• Bardalez Gagliuffi, Daniella Carolina
• Beichman, Charles
• Eisenhardt, Peter
• Gelino, Christopher R
• Gharib-Nezhad, Ehsan
• Gonzales, Eileen
• Marocco, Federico
• Rothermich, Austin James
• Whiteford, Niall

Titel

Methane emission from a cool brown dwarf

Ist Teil von

• Nature (London), 2024-04, Vol.628 (8008), p.511-514N

Ort / Verlag

England: Nature Publishing Group

Erscheinungsjahr

2024

Link zum Volltext

Beschreibungen/Notizen

• Beyond our Solar System, aurorae have been inferred from radio observations of isolated brown dwarfs . Within our Solar System, giant planets have auroral emission with signatures across the electromagnetic spectrum including infrared emission of H and methane. Isolated brown dwarfs with auroral signatures in the radio have been searched for corresponding infrared features, but only null detections have been reported . CWISEP J193518.59-154620.3. (W1935 for short) is an isolated brown dwarf with a temperature of approximately 482 K. Here we report James Webb Space Telescope observations of strong methane emission from W1935 at 3.326 μm. Atmospheric modelling leads us to conclude that a temperature inversion of approximately 300 K centred at 1-10 mbar replicates the feature. This represents an atmospheric temperature inversion for a Jupiter-like atmosphere without irradiation from a host star. A plausible explanation for the strong inversion is heating by auroral processes, although other internal and external dynamical processes cannot be ruled out. The best-fitting model rules out the contribution of H emission, which is prominent in Solar System gas giants. However, this is consistent with rapid destruction of H at the higher pressure where the W1935 emission originates .