The solar activity has been observed to vary at various time scales, of which the 11-year solar cycle is the most prominent one. Since the Sun provides the main external energy to the Earth, knowledge of solar variability ...

The radial velocity method has been used to discover hundreds of extrasolar planets in the past two decades. The continuous improvements in radial velocity precision have revealed several rocky planets in the habitable ...

The challenge of nanometric imaging drives intense efforts in applied sciences and fundamental research. Following the physical law of diffraction, the utilization of extreme ultraviolet (EUV) or X-ray radiation for imaging ...

This thesis reports on the three-dimensional analysis of coronal mass ejections (CMEs) in order to answer questions about their morphology and to derive their three-dimensional geometry. The questions are about the ...

It has been known for a few decades that acoustic oscillations are affected by stellar activity. In the case of the Sun global acoustic modes show a variation with the 11-year cycle and a similar phenomenon has been observed ...

Numerical simulations of the Geodynamo have reproduced many of the features of the Earth's magnetic field. An ensemble of these simulations has been used to formulate a predictive scaling law which agrees with the Earth's ...

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 ...

Measurements of rotation and differential rotation for more than 20,000 active Kepler stars.