Browsing Fakultät für Physik (inkl. GAUSS) by Referee "Dreizler, Stefan Prof. Dr."
Now showing items 1-20 of 43
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Activity of M dwarfs in the CARMENES sample
(2021-11-16)The Calar Alto high-Resolution search for M dwarfs with Exo-earths with Near-infrared and optical Echelle Spectrographs (CARMENES) has been searching and finding planets for five years by looking for periodic Doppler-shift ... -
Analysis of MIRO/Rosetta Data
(2019-02-12)In August 2014, the Rosetta spacecraft completed its ten year journey when it arrived at its target destination, the comet 67P/Churyumov-Gerasimenko. The Rosetta mission was a flagship endeavour for the European Space ... -
Analysis of time series of solar-like oscillations - Applications to the Sun and HD52265
(2011-08-25)The study of stellar oscillations allows one to constrain the structure and dynamics of stellar interiors to a precision that cannot be achieved with other methods. This dissertation focusses ... -
Asteroseismic inferences from red-giant stars
(2019-03-29)The analysis of high-precision long-term photometric time-series of data from the NASA Kepler space mission (2008 − 2012) has revolutionized the field of red-giant seismology. Solar-like oscillations could be detected ... -
Cycle-related solar vacuum ultraviolet (VUV) variability
(2015-11-09)Various studies has shown that the Sun was in an extremely inactive state during the prolonged minimum of the cycle 23 compared to other recent minima. Following these studies, in this thesis work, it was tried to have a ... -
Differential rotation in Sun-like stars from surface variability and asteroseismology
(2016-07-15)Thanks to helioseismology we know the internal rotation of the Sun as a function of radius and latitude. The presence of a shear at the base of the solar convection zone is thought to play a key role in the generation of ... -
Elliptical instability of compressible flow and dissipation in rocky planets for strong tidal forcing
(2016-02-02)This thesis is divided into three main parts, in accordance with Chapters 2, 3 and 4. In the first part, Chap. 2, we investigate the elliptical instability. We calculate the growth rates of the elliptical instability under ... -
Exoplanet Atmosphere Characterization with High-Resolution Doppler Spectroscopy
(2023-03-24)Ultra-hot Jupiters (UHJs) are a class of giant strongly irradiated exoplanets with dayside temperatures exceeding 2200 K. Due to their elevated temperatures, these objects are prime targets for atmospheric characterization ... -
Exploring the solar paradigm to explain stellar variability
(2021-07-13)The unprecedented precision of broadband stellar photometry achieved with the planet hunting missions CoRoT and Kepler initiated a new era in examining the magnetically driven brightness variations of hundreds of thousands ... -
Fabry-Pérot etalons for high precision radial velocity calibration
(2014-06-24)The current generation of astronomical spectrographs can measure radial velocity signals of exoplanets down to a few m/s, in ideal cases even 60 cm/s can be achieved. This led to the discovery of rocky planets with masses ... -
Follow-up and dynamical analysis of Kepler targets with transit timing variations
(2020-06-04)The exact characterisation of planets, their host stars and the structure of their systems is an essential part of exoplanet research. This helps to understand the formation and evolution of planetary systems. Planets ... -
Gravitational Microlensing: GPU-based Simulation Algorithms and the Information Content of Light Curves
(2011-07-22)The simulation of gravitational microlensing light curves is a time-consuming effort, but essential for confirming potential planetary microlensing events. In this thesis a point-wise binary ... -
Heizung der Atmosphären Weißer Zwerge durch Zyklotronstrahlung am Beispiel des Polars AM Herculis
(2005-07-13)This thesis investigates the modelling of hydrogen-rich atmospheres of white dwarfs which are irradiated by an external source.Polars are semi-detached close binary systems which consist ... -
High-resolution spectroscopy of low-mass stars
(2015-03-23)High-resolution spectroscopy is employed to investigate a large sample of open cluster low-mass stars. The stellar rotation and magnetic activity of these stars are measured and their correlation is studied. I find in ... -
How does stellar convection impact the detection of small planets at high radial velocity precision?
(2022-08-15)One of the big driving forces behind exoplanet research is the search for an Earth-twin to answer the old question of whether or not humanity is alone in the universe. According to simple logic as well as our current ... -
Linienformation in M Klasse Sternen
(2010-12-14)The measurement of line broadening in cool stars is, in general, a difficult task. In order to detect slow rotation or weak magnetic fields, an accuracy of 1 km/s is needed. In this regime, ... -
Magnetic and activity cycles of cool stars
(2017-10-17)Cool stars are known to exhibit weak to strong magnetic activity. Our nearest cool star, the Sun, is a middle aged and moderately active star with a cyclic generation of its magnetic field, which results in a 22 year ... -
Magnetohydrodynamic Simulation of Reconnection in Turbulent Astrophysical Plasmas
(2016-08-31)Turbulence is ubiquitous at large-Reynolds-number astrophysical plasmas like in the Solar corona. In such environments, the turbulence is thought to enhance the energy conversion rate by magnetic reconnection above ... -
Massively parallel spectroscopy of sources in Galactic globular clusters
(2021-10-04)Globular clusters (GCs) consist of hundreds of thousands of stars, densely packed into a spherical shape. Not only do GC contain ordinary main sequence and red giant stars, but also the products of frequent stellar ... -
Measuring vortical flows in the solar interior
(2015-09-28)This thesis focuses on observations of the effects of rotation on solar convection at the length scales of supergranulation and larger (>30 Mm). Rotation drives vortical flows through the Coriolis force and causes anisotropic ...