TY - THES A1 - Keles, Engin T1 - Atmospheric properties and dynamics of gaseous exoplanets inferred from high-resolution alkali line transmission spectroscopy N2 - The characterization of exoplanets applying high-resolution transmission spectroscopy ini- tiated a new era making it possible to trace atmospheric signature at high altitudes in exoplanet atmospheres and to determine atmospheric properties which enrich our under- standing of the formation and evolution of the solar system. In contrast to what is observed in our solar system, where gaseous planets orbit at wide orbits, Jupiter type exoplanets were detected in foreign stellar systems surrounding their host stars within few days, in close orbits, the so called hot- and ultra-hot Jupiters. The most well studied ones are HD209458b and HD189733b, which are the first exoplanets where absorption is detected in their atmospheres, namely from the alkali line sodium. For hot Jupiters, the resonant alkali lines are the atmospheric species with one of the strongest absorption signatures, due to their large absorption cross-section. However, al- though the alkali lines sodium and potassium were detected in low-resolution observations for various giant exoplanets, potassium was absent in different high-resolution investiga- tions in contrast to sodium. The reason for this is quite puzzling, since both alkalis have very similar physical and chemical properties (e.g. condensation and ionization proper- ties). Obtaining high-resolution transit observations of HD189733b and HD209458b, we were able to detect potassium on HD189733b (Manuscript 1), which was the first high-resolution detection of potassium on an exoplanet. The absence of potassium on HD209458b could be reasoned by depletion processes, such as condensation or photo-ionization or high-altitude clouds. In a further study (Manuscript II), we resolved the potassium line and compared this to a previously detected sodium absorption on this planet. The comparison showed, that the potassium lines are either tracing different altitudes and temperatures compared to the sodium lines, or are depleted so that the planetary Na/K- ratio is way larger than the stellar one. A comparison of the alkali lines with synthetic line profiles showed that the sodium lines were much broader than the potassium lines, probably being induced by winds. To investigate this, the effect of zonal streaming winds on the sodium lines on Jupiter-type planets is investigated in a further study (Manuscript III), showing that such winds can significantly broaden the Na- lines and that high-resolution observations can trace such winds with different properties. Furthermore, investigating the Na-line observations for different exoplanets, I showed that the Na-line broadening follows a trend with cooler planets showing stronger line broadening and so hinting on stronger winds, matching well into theoretical predictions. Each presented manuscript depends on the re- sults published within the previous manuscript, yielding a unitary study of the exoplanet HD189733b. The investigation of the potassium absorption required to account for different effects: The telluric lines removal and the effect of center-to-limb variation (see Manuscript I), the residual Rossiter-Mc-Laughlin effect (see Manuscript II) and the broadening of spectral lines on a translucent atmospheric ring by zonal jet streams (see Manuscript III). This thesis shows that high-resolution transmission spectroscopy is a powerful tool to probe sharp alkali line absorption on giant exoplanet atmospheres and to investigate on the properties and dynamics of hot Jupiter type atmospheres. KW - planets and satellites: atmospheres KW - planets and satellites: composition KW - planets and satellites: gaseous planets KW - exoplanets Y1 - 2021 ER - TY - JOUR A1 - Eigmüller, Philipp A1 - Chaushev, Alexander A1 - Gillen, Edward A1 - Smith, Alexis A1 - Nielsen, Louise D. A1 - Turner, Oliver A1 - Csizmadia, Szilard A1 - Smalley, Barry A1 - Bayliss, Daniel A1 - Belardi, Claudia A1 - Bouchy, Francois A1 - Burleigh, Matthew R. A1 - Cabrera, Juan A1 - Casewell, Sarah L. A1 - Chazelas, Bruno A1 - Cooke, Benjamin F. A1 - Erikson, Anders A1 - Gansicke, Boris T. A1 - Guenther, Maximilian N. A1 - Goad, Michael R. A1 - Grange, Andrew A1 - Jackman, James A. G. A1 - Jenkins, James S. A1 - McCormac, James A1 - Moyano, Maximiliano A1 - Pollacco, Don A1 - Poppenhäger, Katja A1 - Queloz, Didier A1 - Raynard, Liam A1 - Rauer, Heike A1 - Udry, Stephane A1 - Walker, Simon. R. A1 - Watson, Christopher A. A1 - West, Richard G. A1 - Wheatley, Peter J. T1 - NGTS-5b BT - a highly inflated planet offering insights into the sub-Jovian desert JF - Astronomy and astrophysics : an international weekly journal N2 - Context. Planetary population analysis gives us insight into formation and evolution processes. For short-period planets, the sub-Jovian desert has been discussed in recent years with regard to the planet population in the mass/period and radius/period parameter space without taking stellar parameters into account. The Next Generation Transit Survey (NGTS) is optimised for detecting planets in this regime, which allows for further analysis of the sub-Jovian desert. Aims. With high-precision photometric surveys (e.g. with NGTS and TESS), which aim to detect short period planets especially around M/K-type host stars, stellar parameters need to be accounted for when empirical data are compared to model predictions. Presenting a newly discovered planet at the boundary of the sub-Jovian desert, we analyse its bulk properties and use it to show the properties of exoplanets that border the sub-Jovian desert. Methods. Using NGTS light curve and spectroscopic follow-up observations, we confirm the planetary nature of planet NGTS-5b and determine its mass. Using exoplanet archives, we set the planet in context with other discoveries. Results. NGTS-5b is a short-period planet with an orbital period of 3.3569866 +/- 0.0000026 days. With a mass of 0.229 +/- 0.037 M-Jup and a radius of 1.136 +/- 0.023 R-Jup, it is highly inflated. Its mass places it at the upper boundary of the sub-Jovian desert. Because the host is a K2 dwarf, we need to account for the stellar parameters when NGTS-5b is analysed with regard to planet populations. Conclusions. With red-sensitive surveys (e.g. with NGTS and TESS), we expect many more planets around late-type stars to be detected. An empirical analysis of the sub-Jovian desert should therefore take stellar parameters into account. KW - planets and satellites: detection KW - planets and satellites: gaseous planets Y1 - 2019 U6 - https://doi.org/10.1051/0004-6361/201935206 SN - 1432-0746 VL - 625 PB - EDP Sciences CY - Les Ulis ER -