Jupiter as an exoplanet: UV to nir transmission spectrum reveals hazes, a Na layer, and possibly stratospheric H2O-ice clouds

Currently, the analysis of transmission spectra is the most successful technique to probe the chemical composition of exoplanet atmospheres. However, the accuracy of these measurements is constrained by observational limitations and the diversity of possible atmospheric compositions. Here, we show t...

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Detalles Bibliográficos
Autores: Montañés-Rodríguez, Pilar, González-Merino, B., Pallé, Enric, López-Puertas, Manuel, García-Melendo, E.
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2015
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/398122
Acceso en línea:http://hdl.handle.net/10261/398122
Access Level:acceso abierto
Palabra clave:Eclipses
Planets and satellites: atmospheres
Planets and satellites: gaseous planets
Planets and satellites: individual (Jupiter, Ganymede)
Descripción
Sumario:Currently, the analysis of transmission spectra is the most successful technique to probe the chemical composition of exoplanet atmospheres. However, the accuracy of these measurements is constrained by observational limitations and the diversity of possible atmospheric compositions. Here, we show the UV–VIS–IR transmission spectrum of Jupiter as if it were a transiting exoplanet, obtained by observing one of its satellites, Ganymede, while passing through Jupiter’s shadow, i.e., during a solar eclipse from Ganymede. The spectrum shows strong extinction due to the presence of clouds (aerosols) and haze in the atmosphere and strong absorption features from CH4. More interestingly, the comparison with radiative transfer models reveals a spectral signature, which we attribute here to a Jupiter stratospheric layer of crystalline H2O ice. The atomic transitions of Na are also present. These results are relevant for the modeling and interpretation of giant transiting exoplanets. They also open a new technique to explore the atmospheric composition of the upper layers of Jupiter’s atmosphere. © 2015. The American Astronomical Society. All rights reserved.