[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 identical<SUP>1,2</SUP>. 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 scenarios<SUP>3</SUP>. However, the complexity of planet formation requires further tracers, as the unambiguous interpretation of the measured C/O ratio is fraught with complexity<SUP>4</SUP>. Isotope ratios, such as deuterium to hydrogen and <SUP>14</SUP>N/<SUP>15</SUP>N, offer a promising avenue to gain further insight into this formation process, mirroring their use within the Solar System<SUP>5-7</SUP>. For exoplanets, only a handful of constraints on <SUP>12</SUP>C/<SUP>13</SUP>C exist, pointing to the accretion of <SUP>13</SUP>C-rich ice from beyond the CO iceline of the disks<SUP>8,9</SUP>. Here we report on the mid-infrared detection of the <SUP>14</SUP>NH<SUB>3</SUB> and <SUP>15</SUP>NH<SUB>3</SUB> 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 <SUP>14</SUP>N/<SUP>15</SUP>N 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 <SUP>15</SUP>N isotope<SUP>10</SUP>, we expect that <SUP>15</SUP>NH<SUB>3</SUB> 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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