Keles, E.E.KelesKitzmann, D.D.KitzmannMallonn, M.M.MallonnAlexoudi, X.X.AlexoudiFossati, L.L.FossatiPino, LorenzoLorenzoPinoSeidel, J. V.J. V.SeidelCarroll, T. A.T. A.CarrollSteffen, M.M.SteffenIlyin, I.I.IlyinPoppenhäger, K.K.PoppenhägerStrassmeier, K. G.K. G.Strassmeiervon Essen, C.C.von EssenNASCIMBENI, VALERIOVALERIONASCIMBENITurner, J. D.J. D.Turner2022-04-012022-04-0120200035-8711http://hdl.handle.net/20.500.12386/32074High spectral resolution transmission spectroscopy is a powerful tool to characterize exoplanet atmospheres. Especially for hot Jupiters, this technique is highly relevant, due to their high-altitude absorption, e.g. from resonant sodium (Na I) and potassium (K I) lines. We resolve the atmospheric K I absorption on HD189733b with the aim to compare the resolved K I line and previously obtained high-resolution Na I-D line observations with synthetic transmission spectra. The line profiles suggest atmospheric processes leading to a line broadening of the order of ˜10 km/s for the Na I-D lines and only a few km/s for the K I line. The investigation hints that either the atmosphere of HD189733b lacks a significant amount of K I or the alkali lines probe different atmospheric regions with different temperature, which could explain the differences we see in the resolved absorption lines.STAMPAenArticle10.1093/mnras/staa2435https://academic.oup.com/mnras/article-abstract/498/1/1023/5892592?redirectedFrom=fulltext&login=false2020MNRAS.498.1023KFIS/05 - ASTRONOMIA E ASTROFISICA