Pre-Main Sequence stars are young stars whose cores are not dense and hot enough to ignite the thermonuclear reactions that will power them for the rest of their evolution. These stars are sorted in three classes: the youngest stars are the class I sources, still embedded in an accreting envelope of gas; class II stars have dispersed their accreting envelope
Most of the stars, mainly the low mass stars, produce their own magnetic field in their interior. The interaction between the magnetic field and stellar plasma is the cause of phenomena such as photosperic spots, faculae, protuberances, coronal mass ejections, and flares. The study of this activity is important both because it reveals how intense magnetic fields interact with high-temperature
The study of star-forming regions of our Galaxy is one of the main research topic of the Astronomical Observatory of Palermo. This because they can provide crucial information on how large molecular clouds collapse and form stars, on the early stellar evolutionary stages, on the formation of planetary systems, the formation and dispersion of protoplanetary disks, and the history and