¹⁵NH₃ in the atmosphere of a cool brown dwarf

Autor(en)

David Barrado, Paul Mollière, Polychronis Patapis, Michiel Min, Pascal Tremblin, Francisco Ardevol Martinez, Niall Whiteford, Malavika Vasist, Ioannis Argyriou, Matthias Samland, Pierre Olivier Lagage, Leen Decin, Rens Waters, Thomas Henning, María Morales-Calderón, Manuel Guedel, Bart Vandenbussche, Olivier Absil, Pierre Baudoz, Anthony Boccaletti, Jeroen Bouwman, Christophe Cossou, Alain Coulais, Nicolas Crouzet, René Gastaud, Alistair Glasse, Adrian M. Glauser, Inga Kamp, Sarah Kendrew, Oliver Krause, Fred Lahuis, Michael Mueller, Göran Olofsson, John Pye, Daniel Rouan, Pierre Royer, Silvia Scheithauer, Ingo Waldmann, Luis Colina, Ewine F. van Dishoeck, Tom Ray, Göran Östlin, Gillian Wright

Abstrakt

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^1,2. 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 System^5–7. 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 disks^8,9. 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.

Organisation(en)

Institut für Astrophysik

Externe Organisation(en)

European Space Astronomy Centre (ESA), Max-Planck-Institut für Astronomie, Eidgenössische Technische Hochschule Zürich, SRON Netherlands Institute for Space Research , Université de Versailles-Saint-Quentin-en-Yvelines, University of Groningen, University of Edinburgh, American Museum of Natural History, Université de Liège, Katholieke Universiteit Leuven, Université Paris Saclay, Radboud University, Université de recherche Paris Sciences et Lettres, Leiden University, The Royal Observatory, Edinburgh, Stockholm University, University of Leicester, University College London, Dublin Institute for Advanced Studies, Oskar Klein Centre

Journal

Nature

Band

624

Seiten

263-266

Anzahl der Seiten

4

ISSN

0028-0836

DOI

https://doi.org/10.1038/s41586-023-06813-y

Publikationsdatum

12-2023

Peer-reviewed

Ja

ÖFOS 2012

103003 Astronomie, 103004 Astrophysik

ASJC Scopus Sachgebiete

General

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/1be08341-06c6-4171-a2ab-87cf19999636