The study of the exoplanets orbiting around young stars (e.g., younger than a few tens of million of years) offer the important opportunity for studying the early evoalutionary phases of those processes that shape the architecture of planetary systems. However, it is quite difficult to detect and study exoplanets around young stars, because of their low number, the complexity of their
Some of the exoplanets known so far belong to classes that do not exist in our Solar System. For instance, the class of the Hot Jupiters, i.e., gaseous giant planets orbiting at close distances from their stars (typically less than 0.5 AU, Astronomical Unit, where a 1 AU is the average distance between Sun and Earth, about 150 million km).
