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Faherty JK, Burningham B, Gagné J, Suárez G, Vos JM, Alejandro Merchan S, Morley CV, Rowland M, Lacy B, Kiman R, Caselden D, Kirkpatrick JD, Meisner A, Schneider AC, Kuchner MJ, Bardalez Gagliuffi DC, Beichman C, Eisenhardt P, Gelino CR, Gharib-Nezhad E, Gonzales E, Marocco F, Rothermich AJ, Whiteford N. Methane emission from a cool brown dwarf. Nature 2024; 628:511-514. [PMID: 38632480 PMCID: PMC11023930 DOI: 10.1038/s41586-024-07190-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Accepted: 02/09/2024] [Indexed: 04/19/2024]
Abstract
Beyond our Solar System, aurorae have been inferred from radio observations of isolated brown dwarfs1,2. Within our Solar System, giant planets have auroral emission with signatures across the electromagnetic spectrum including infrared emission of H3+ and methane. Isolated brown dwarfs with auroral signatures in the radio have been searched for corresponding infrared features, but only null detections have been reported3. 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 H3+ emission, which is prominent in Solar System gas giants. However, this is consistent with rapid destruction of H3+ at the higher pressure where the W1935 emission originates4.
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Affiliation(s)
- Jacqueline K Faherty
- Department of Astrophysics, American Museum of Natural History, New York, NY, USA.
- Department of Physics, The Graduate Center City University of New York, New York, NY, USA.
| | - Ben Burningham
- Department of Physics, Astronomy and Mathematics, University of Hertfordshire, Hatfield, UK
| | - Jonathan Gagné
- Planétarium Rio Tinto Alcan, Montreal, Quebec, Canada
- Département de Physique, Université de Montréal, Montreal, Quebec, Canada
| | - Genaro Suárez
- Department of Astrophysics, American Museum of Natural History, New York, NY, USA
| | - Johanna M Vos
- Department of Astrophysics, American Museum of Natural History, New York, NY, USA
- School of Physics, Trinity College Dublin, The University of Dublin, Dublin, Ireland
| | - Sherelyn Alejandro Merchan
- Department of Astrophysics, American Museum of Natural History, New York, NY, USA
- Department of Physics & Astronomy, Hunter College, New York, NY, USA
| | - Caroline V Morley
- Department of Astronomy, University of Texas at Austin, Austin, TX, USA
| | - Melanie Rowland
- Department of Astronomy, University of Texas at Austin, Austin, TX, USA
| | - Brianna Lacy
- Department of Astronomy, University of Texas at Austin, Austin, TX, USA
| | - Rocio Kiman
- Department of Astronomy, California Institute of Technology, Pasadena, CA, USA
| | - Dan Caselden
- Department of Astrophysics, American Museum of Natural History, New York, NY, USA
| | | | - Aaron Meisner
- NSF's National Optical-Infrared Astronomy Research Laboratory, Tucson, AZ, USA
| | | | - Marc Jason Kuchner
- Exoplanets and Stellar Astrophysics Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | - Daniella Carolina Bardalez Gagliuffi
- Department of Astrophysics, American Museum of Natural History, New York, NY, USA
- Department of Physics & Astronomy, Amherst College, Amherst, MA, USA
| | | | - Peter Eisenhardt
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
| | | | | | - Eileen Gonzales
- Department of Physics, San Francisco State University, San Francisco, CA, USA
- Department of Astronomy and Carl Sagan Institute, Cornell University, Ithaca, NY, USA
| | | | - Austin James Rothermich
- Department of Astrophysics, American Museum of Natural History, New York, NY, USA
- Department of Physics, The Graduate Center City University of New York, New York, NY, USA
| | - Niall Whiteford
- Department of Astrophysics, American Museum of Natural History, New York, NY, USA
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Luhman KL, Hapich CJ. NEW CANDIDATES FOR PLANETARY-MASS BROWN DWARFS IN IC 348. THE ASTRONOMICAL JOURNAL 2020; 160:57. [PMID: 32753765 PMCID: PMC7402408 DOI: 10.3847/1538-3881/ab96bb] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
We have used infrared images obtained with the Wide Field Camera 3 on board the Hubble Space Telescope to search for planetary-mass brown dwarfs in the star-forming cluster IC 348. In those images, we have identified 12 objects that have colors indicative of spectral types later than M8, corresponding to masses of ≲ 30 M Jup at the age of IC 348. The four brightest candidates have been observed with spectroscopy, all of which are confirmed to have late types. Two of those candidates appear to be young, and thus are likely members of the cluster, while the ages and membership of the other two candidates are uncertain. One of the former candidates is the faintest known member of IC 348 in extinction-corrected K s and is expected to have a mass of 4-5 M Jup based on evolutionary models and an assumed age of 3 Myr. Four of the remaining eight candidates have ground-based photometry that further supports their candidacy as brown dwarfs, some of which are fainter (and potentially less massive) than the known members.
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Affiliation(s)
- K L Luhman
- Department of Astronomy and Astrophysics, The Pennsylvania State University, University Park, PA 16802
- Center for Exoplanets and Habitable Worlds, The Pennsylvania State University, University Park, PA 16802, USA
| | - C J Hapich
- Department of Astronomy and Astrophysics, The Pennsylvania State University, University Park, PA 16802
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