J/A+A/640/L5ivo://CDS.VizieR/J/A+A/640/L5doi:10.26093/cds/vizier.36409005CDSYan F.Palle E.Reiners A.Molaverdikhani K.Casasayas-Barris N.,Nortmann L.Chen G.Molliere P.Stangret M.2021-03-29T12:28:58Z2020-07-29T06:44:16ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frmultiple-starsexoplanetsspectroscopyTemperature inversion layers are predicted to be present in ultra-hot giant planet atmospheres. Although such inversion layers have recently been observed in several ultra-hot Jupiters, the chemical species responsible for creating the inversion remain unidentified. Here, we present observations of the thermal emission spectrum of an ultra-hot Jupiter, WASP-189b, at high spectral resolution using the HARPS-N spectrograph. Using the cross-correlation technique, we detect a strong FeI signal. The detected FeI spectral lines are found in emission, which is direct evidence of a temperature inversion in the planetary atmosphere. We further performed a retrieval on the observed spectrum using a forward model with an MCMC approach. When assuming a solar metallicity, the best-fit result returns a temperature of 4320 K at the top of the inversion, which is significantly hotter than the planetary equilibrium temperature (2641 K). The temperature at the bottom of the inversion is determined as 2200 K. Such a strong temperature inversion is probably created by the absorption of atomic species like FeI.2020A&A...640L...5Yhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/640/L5CatalogResearchIsServedByTAP VizieR generic servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/640/L5https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/640/L5http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/640/L5https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/640/L5https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/640/L5http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/640/L5GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapdefaultJ/A+A/640/L5/spectrumNormalised thermal emission spectrum of WASP-189brecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintlambdaWavelength0.1nmem.wldoubleNFluxNormalised Fluxphot.fluxdoubleJ/A+A/640/L5/snrSignal-to-noise ratio of each wavelength pointrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintlambdaWavelength0.1nmem.wldoubleSNRSignal-to-noise ratiostat.snrdouble