Stellar activity is one of the principal obstacles to achieving sub 1 m/s radial velocity precision in exoplanet detection surveys. Understanding how stellar activity affects the stellar environment is crucial to mitigating ...

Solar activity undergoes variations over many different timescales. The main periodicity is 11 years, called Schwabe cycle. In addition to the 11-year cycle, shorter periodic variations known as Rieger cycles have been ...

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 ...

Extrasolar giant planets (EGP) in a close-in orbit undergo extreme irradiation by their host star. Emission of H$_{3}^{+}$ is expected to support the stabilization of the planetary atmosphere, since the ion radiates in the ...

After the first confirmed detection of an exoplanet in 1995, their number has significantly increased to 3 557 confirmed planets around other stars (www.exoplanet.eu, Dec. 2016). The most successful techniques for planet ...

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 ...

In this thesis, the magnetoconvective processes in the nearsurface layers of cool main-sequence stars were studied in 24 three-dimensional local “box-in-a-star” simulations. For each of six sets of stellar parameters ...