Summary:
An interesting class of celestial objects studied in this thesis is what are called super-puffs. The special feature of these objects is their extremely low density, which is of the order of 0.1 gr/cm^3. One of the scenarios that explain the observed densities assumes that they are planets of smaller radius with rings orbiting around them. In this thesis this scenario was followed and a set of long-period planets was studied, using observational data obtained from the Kepler Space Telescope. Using transit photometry, by the appropriate processing of the data and by fitting theoretical models on them, the parameters of the system host star-planet-ring can be calculated. Comparing the results provided by the fitting of a ringed and a non-ringed model, it is possible to detect indications of ring presence. In this way, someone can identify planets that need further observations.
Today, it is known that rings are a common feature of the celestial bodies in the Solar System. They are found orbiting around planets, and so around dwarf planets and asteroids. However, discovering rings around extrasolar planets is still a challenge. It is therefore essential to detect rings around extrasolar planets beyond the Solar System. By investigating them, questions can be answered about the conditions under which they are formed, their evolution over time and their physical characteristics (composition, mass).
Keywords:
exoplanets, rings, photometry, transits, Kepler
