Ultraviolet Legacy Library of Young Stars as Essential Standards (ULLYSES): Data Release I

We present the first Data Release (DR1) from the Hubble Space Telescope (HST) Ultraviolet Legacy Library of Young Stars as Essential Standards (ULLYSES) program, a Director's Discretionary program devoting approximately 1000 HST orbits to the production of an ultraviolet spectroscopic library of young high- and low-mass stars in the local universe. The science products in this release are combined from individual, extracted and calibrated spectra obtained with the COS and STIS instruments aboard HST. Products are made using both archival HST data and new HST observations obtained through the ULLYSES program. DR1 acts as the first step toward completing a goal of generating a fully public data set for the purpose of enabling, supporting, and stimulating a broad range of transformative astrophysical research.