%0 Book Section %T The T Tauri stars (TTSs) physics as studied with the IUE: From activity to accretion publisher European Space Agency %D 1998 %U 92-9092-652-X %@ https://hdl.handle.net/20.500.14352/60575 %X The International Ultraviolet Explorer (IUE) has been contemporary to the rapid development of the research on star formation. The IUE has contributed significantly to the understanding of the atmospheres of the T Tauri stars (TTSs) as well as to the study of the accretion physics in pre-main sequence stars; the main findings in these two fields are summarized in this contribution. A brief summary of the contains of the IUE Final Archive on TTSs is also provided. %~