Ultraviolet Spectroscopy of T Tauri Stars with ULLYSES

The Hubble Space Telescope's Ultraviolet Legacy Library of Young Stars as Essential Standards (ULLYSES) is a Director’s Discretionary program of approximately 1,000 orbits that is producing an ultraviolet spectroscopic library of young high- and low-mass stars in the local universe. This presentation addresses the low-mass stars; these are T Tauri stars for which ULLYSES is sampling a broad range of stellar masses and accretion rates. In addition to data already in the MAST archive, we are obtaining single-epoch COS and STIS spectra of about 67 survey targets and time monitoring of 4 prototypical targets. The monitoring targets will be observed four times per rotational period over three periods, with this pattern repeated nine to twelve months later. Observations began in Fall 2020.