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
di Mario Giuseppe Guarcello ( segui mguarce) A recent study by a team of researchers of INAF-Astronomical Observatory of Palermo, the University of Palermo, and the University of Madrid, recently published on the Astrophysical Journal, shows that enormous flares in the young stars in Orion are due to large magnetic loops connecting the stars and their protoplanetary disks,