A secondary atmosphere on the rocky exoplanet 55 Cancri e.

Autor: Hu R; Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA. renyu.hu@jpl.nasa.gov.; Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, USA. renyu.hu@jpl.nasa.gov., Bello-Arufe A; Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA., Zhang M; Department of Astronomy and Astrophysics, University of Chicago, Chicago, IL, USA., Paragas K; Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, USA., Zilinskas M; SRON Netherlands Institute for Space Research, Leiden, The Netherlands., van Buchem C; Leiden Observatory, Leiden University, Leiden, The Netherlands., Bess M; Department of Physics and Astronomy, University of New Mexico, Albuquerque, NM, USA., Patel J; Department of Astronomy, Stockholm University, Stockholm, Sweden., Ito Y; Division of Science, National Astronomical Observatory of Japan (NAOJ), Mitaka, Japan.; Department of Physics and Astronomy, University College London, London, United Kingdom., Damiano M; Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA., Scheucher M; Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA., Oza AV; Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA., Knutson HA; Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, USA., Miguel Y; SRON Netherlands Institute for Space Research, Leiden, The Netherlands.; Leiden Observatory, Leiden University, Leiden, The Netherlands., Dragomir D; Department of Physics and Astronomy, University of New Mexico, Albuquerque, NM, USA., Brandeker A; Department of Astronomy, Stockholm University, Stockholm, Sweden., Demory BO; Center for Space and Habitability, University of Bern, Bern, Switzerland.; Space Research and Planetary Sciences, Physics Institute, University of Bern, Bern, Switzerland.
Jazyk: angličtina
Zdroj: Nature [Nature] 2024 Jun; Vol. 630 (8017), pp. 609-612. Date of Electronic Publication: 2024 May 08.
DOI: 10.1038/s41586-024-07432-x
Abstrakt: Characterizing rocky exoplanets is a central aim of astronomy, and yet the search for atmospheres on rocky exoplanets has so far resulted in either tight upper limits on the atmospheric mass 1-3 or inconclusive results 4-6 . The 1.95R Earth and 8.8M Earth planet 55 Cancri e (abbreviated 55 Cnc e), with a predominantly rocky composition and an equilibrium temperature of around 2,000 K, may have a volatile envelope (containing molecules made from a combination of C, H, O, N, S and P elements) that accounts for up to a few percent of its radius 7-13 . The planet has been observed extensively with transmission spectroscopy 14-22 and its thermal emission has been measured in broad photometric bands 23-26 . These observations disfavour a primordial H 2 /He-dominated atmosphere but cannot conclusively determine whether the planet has a secondary atmosphere 27,28 . Here we report a thermal emission spectrum of the planet obtained by the NIRCam and MIRI instruments aboard the James Webb Space Telescope (JWST) from 4 to 12 μm. The measurements rule out the scenario in which the planet is a lava world shrouded by a tenuous atmosphere made of vaporized rock 29-32 and indicate a bona fide volatile atmosphere that is probably rich in CO 2 or CO. This atmosphere can be outgassed from and sustained by a magma ocean.
(© 2024. The Author(s), under exclusive licence to Springer Nature Limited.)
Databáze: MEDLINE
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