T Tauri phase

In astronomy, phase in the life-cycle of a star named after a variable star in the constellation of Taurus. T Tauri is believed to be a protostar, a body that has condensed out of a cloud of dust and gas and has not yet started hydrogen burning. It is the prototype for a class of similar stars known as T Tauri stars that are characterized by irregular variability and the emission of substantial amounts of gas and dust at speeds of 100–200 kps/62–124 mps. T Tauri stars have masses in the range of 0.2–2.0 times the mass of the Sun and can lose up to half the mass of the Sun before settling down to hydrogen burning. It is thought that most stars, including the Sun, have passed through a T Tauri phase.