Blazars are a highly variable subclass of active galactic nuclei that have been observed to vary significantly during a single night. This intranight variability remains a debated phenomenon, with various mechanisms proposed to explain the behaviour including jet energy density evolution or system geometric changes. We present the results of an

Context. The determination of planetary densities from the masses derived with the radial velocity (RV) and transit-timing variation (TTV) methods reveals discrepancies. Specifically, planets detected through RV exhibit higher densities than those detected through TTV, even though their radii are similar. Understanding the origins of these

The superb image quality, stability, and sensitivity of JWST permit deconvolution techniques to be pursued with a fidelity unavailable to ground-based observations. We present an assessment of several deconvolution approaches to improve image quality and mitigate the effects of the complex JWST point-spread function (PSF). The optimal deconvolution

The evolution of the core rotation rate of red giant stars is a key parameter in understanding the stellar behavior in the late phases of stellar evolution. Thanks to the mixed-dipole modes, we can constrain the core rotation and internal rotational gradient as a star advances through the red-giant phase. This master thesis presents a pipeline

The evolution of stars and their hosting binary systems is a highly interactive process and cannot be investigated in a segregated manner. Due to the constraints drawn by stellar binarity, oscillating red-giant stars in binary systems represent a unique opportunity to study the details of the structure and evolution of stars in the advanced phases

We report the confirmation of a sub-Saturn-size exoplanet, TOI-1194 b, with a mass of about ${0.456}_{-0.051}^{+0.055}$ M J, and a very low mass companion star with a mass of about 96.5 ± 1.5 M J, TOI-1251 B. Exoplanet candidates provided by the Transiting Exoplanet Survey Satellite (TESS) are suitable for further follow-up observations by ground