[en] Brown dwarfs serve as ideal laboratories for studying the atmospheres of giant exoplanets on wide orbits, as the governing physical and chemical processes within them are nearly identical1,2. Understanding the formation of gas-giant planets is challenging, often involving the endeavour to link atmospheric abundance ratios, such as the carbon-to-oxygen (C/O) ratio, to formation scenarios3. However, the complexity of planet formation requires further tracers, as the unambiguous interpretation of the measured C/O ratio is fraught with complexity4. Isotope ratios, such as deuterium to hydrogen and 14N/15N, offer a promising avenue to gain further insight into this formation process, mirroring their use within the Solar System5-7. For exoplanets, only a handful of constraints on 12C/13C exist, pointing to the accretion of 13C-rich ice from beyond the CO iceline of the disks8,9. Here we report on the mid-infrared detection of the 14NH3 and 15NH3 isotopologues in the atmosphere of a cool brown dwarf with an effective temperature of 380 K in a spectrum taken with the Mid-Infrared Instrument (MIRI) of JWST. As expected, our results reveal a 14N/15N value consistent with star-like formation by gravitational collapse, demonstrating that this ratio can be accurately constrained. Because young stars and their planets should be more strongly enriched in the 15N isotope10, we expect that 15NH3 will be detectable in several cold, wide-separation exoplanets.
Research Center/Unit :
STAR - Space sciences, Technologies and Astrophysics Research - ULiège
Disciplines :
Space science, astronomy & astrophysics
Author, co-author :
Barrado, David ✱; Center for Astrobiology, Madrid
Mollière, Paul ✱; Max-Planck-Institute for Astronomy, Heidelberg
Patapis, Polychronis ✱; Institute of Particle Physics and Astrophysics, ETH Zurich, Zürich, Switzerland
Min, Michiel; Netherlands Institute for Space Research
Tremblin, Pascal; Université Paris-Saclay, UVSQ, CNRS, CEA, Gif-sur-Yvette, France
Ardevol Martinez, Francisco; Netherlands Institute for Space Research, -, University of Edinburgh, School of Geosciences, University of Edinburgh, Centre for Astrobiology
Whiteford, Niall; American Museum of Natural History, New York
Vasist, Malavika Vijayendra ; Université de Liège - ULiège > Unités de recherche interfacultaires > Space sciences, Technologies and Astrophysics Research (STAR)
Argyriou, Ioannis; Katholieke University of Leuven, Astronomical Institute
Samland, Matthias; Max-Planck-Institute for Astronomy, Heidelberg
Lagage, Pierre-Olivier; CEA Saclay, Service d'Astrophysique
Decin, Leen; Katholieke University of Leuven, Astronomical Institute
Waters, Rens; Netherlands Institute for Space Research, Radboud University Nijmegen, Department of Astronomy and Physics
Henning, Thomas; Max-Planck-Institute for Astronomy, Heidelberg
Morales-Calderón, María; Center for Astrobiology, Madrid
Guedel, Manuel; Max-Planck-Institute for Astronomy, Heidelberg, -, University of Vienna, Department of Astronomy
Vandenbussche, Bart; Katholieke University of Leuven, Astronomical Institute
Absil, Olivier ; Université de Liège - ULiège > Département d'astrophysique, géophysique et océanographie (AGO)
Baudoz, Pierre; LESIA, Observatoire de Paris, Université PSL, CNRS, Sorbonne Université, Université de Paris Cité, Meudon, France
Boccaletti, Anthony; LESIA, Observatoire de Paris, Université PSL, CNRS, Sorbonne Université, Université de Paris Cité, Meudon, France
Bouwman, Jeroen; Max-Planck-Institute for Astronomy, Heidelberg
Cossou, Christophe; Université Paris-Saclay, CEA, IRFU, Gif-sur-Yvette, France
Coulais, Alain; CEA Saclay, Service d'Astrophysique, -
Crouzet, Nicolas; Leiden Observatory
Gastaud, René; Université Paris-Saclay, CEA, IRFU, Gif-sur-Yvette, France
Glasse, Alistair; Royal Observatory Edinburgh
Glauser, Adrian M.; Institute of Particle Physics and Astrophysics, ETH Zurich, Zürich, Switzerland
Kamp, Inga; Kapteyn Institute of Astronomy, University of Groningen, Groningen, The Netherlands
Kendrew, Sarah; Space Telescope Science Institute, ESA Office, Baltimore, Maryland
Krause, Oliver; Max-Planck-Institute for Astronomy, Heidelberg
Lahuis, Fred; Netherlands Institute for Space Research
Mueller, Michael; Kapteyn Institute of Astronomy, University of Groningen, Groningen, The Netherlands
Olofsson, Göran; AlbaNova University Center
Pye, John; School of Physics &, Astronomy, Space Research Centre, Space Park Leicester, University of Leicester, Leicester, UK
Rouan, Daniel; LESIA, Observatoire de Paris, Université PSL, CNRS, Sorbonne Université, Université de Paris Cité, Meudon, France
Royer, Pierre; Katholieke University of Leuven, Astronomical Institute
Scheithauer, Silvia; Max-Planck-Institute for Astronomy, Heidelberg
Waldmann, Ingo; University College London, Department of Physics and Astronomy
Colina, Luis; Center for Astrobiology, Madrid
van Dishoeck, Ewine F.; Leiden Observatory
Ray, Tom; Dublin Institute for Advanced Studies, School of Cosmic Physics
Östlin, Göran; Stockholm University, Department of Astronomy
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