A rich hydrocarbon chemistry and high C to O ratio in the inner disk around a very low-mass star
Journal article, 2023
Carbon is an essential element for life but how much can be delivered to young planets is still an open question. The chemical characterization of planet-forming disks is a crucial step in our understanding of the diversity and habitability of exoplanets. Very low-mass stars (less than 0.2 M ⊙) are interesting targets because they host a rich population of terrestrial planets. Here we present the James Webb Space Telescope detection of abundant hydrocarbons in the disk of a very low-mass star obtained as part of the Mid-InfraRed Instrument mid-INfrared Disk Survey (MINDS). In addition to very strong and broad emission from C2H2 and its 13C12CH2 isotopologue, C4H2, benzene and possibly CH4 are identified, but water, polycyclic aromatic hydrocarbons and silicate features are weak or absent. The lack of small silicate grains indicates that we can look deep down into this disk. These detections testify to an active warm hydrocarbon chemistry with a high C/O ratio larger than unity in the inner 0.1 astronomical units (AU) of this disk, perhaps due to destruction of carbonaceous grains. The exceptionally high C2H2/CO2 and C2H2/H2O column density ratios indicate that oxygen is locked up in icy pebbles and planetesimals outside the water iceline. This, in turn, will have important consequences for the composition of forming exoplanets.
Author
Benoît Tabone
Leiden University
Institut d'Astrophysique Spatiale
Giulio Bettoni
Max Planck Society
Leiden University
Ewine F. van Dishoeck
Leiden University
Max Planck Society
Aditya M. Arabhavi
University of Groningen
Sierra L. Grant
Max Planck Society
Danny Gasman
KU Leuven
T. Henning
Max Planck Society
I. Kamp
University of Groningen
M. Gudel
Swiss Federal Institute of Technology in Zürich (ETH)
University of Vienna
Max Planck Society
P. O. Lagage
University Paris-Saclay
T. P. Ray
Dublin Institute for Advanced Studies
B. Vandenbussche
KU Leuven
Alain Abergel
Institut d'Astrophysique Spatiale
O. Absil
University of Liège
Ioannis Argyriou
KU Leuven
D. Barrado
Centro de Astrobiologia (CAB)
Anthony Boccaletti
Paris Observatory
J. Bouwman
Max Planck Society
A. Caratti o. Garatti
Istituto nazionale di astrofisica (INAF)
Dublin Institute for Advanced Studies
V. C. Geers
Royal Observatory
A. M. Glauser
Swiss Federal Institute of Technology in Zürich (ETH)
Kay Justtanont
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
F. Lahuis
Netherlands Institute for Space Research (SRON)
M. Mueller
University of Groningen
Cyrine Nehmé
University Paris-Saclay
G. Olofsson
Stockholm University
E. Pantin
University Paris-Saclay
S. Scheithauer
Max Planck Society
C. Waelkens
KU Leuven
L. B.F.M. Waters
Netherlands Institute for Space Research (SRON)
Radboud University
John H Black
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
Valentin Christiaens
University of Liège
Rodrigo Guadarrama
University of Vienna
M. Morales-Calderon
Centro de Astrobiologia (CAB)
Hyerin Jang
Radboud University
Jayatee Kanwar
Institut fur Weltraumforschung
University of Groningen
Nicole Pawellek
University of Vienna
Hungarian Academy of Sciences
G. Perotti
Max Planck Society
Agnès Perrin
Pierre and Marie Curie University (UPMC)
Donna Rodgers-Lee
Dublin Institute for Advanced Studies
Matthias Samland
Max Planck Society
Jürgen Schreiber
Max Planck Society
Kamber Schwarz
Max Planck Society
L. Colina
Centro de Astrobiologia (CAB)
G. Östlin
Stockholm University
Gillian Wright
Royal Observatory
Nature Astronomy
23973366 (eISSN)
Vol. 7 7 805-814Subject Categories
Astronomy, Astrophysics and Cosmology
DOI
10.1038/s41550-023-01965-3