  The Decadal Survey on Astronomy and Astrophysics 2020 (Astro2020) has
recommended that NASA realize a large IR/O/UV space telescope optimized for
high-contrast imaging and spectroscopy of ~25 exo-Earths and transformative
general astrophysics. The NASA Exoplanet Exploration Program (ExEP) has
subsequently released a list of 164 nearby (d<25 pc) targets deemed the most
accessible to survey for potentially habitable exoplanets with the Habitable
Worlds Observatory (HWO). We present a catalog of system properties for the 164
ExEP targets, including 1744 abundance measurements for 14 elements from the
Hypatia Catalog and 924 photometry measurements spanning from 151.6 nm to 22
{\mu}m in the GALEX, Str\"omgren, Tycho, Gaia, 2MASS, and WISE bandpasses. We
independently derive stellar properties for these systems by modeling their
spectral energy distributions with Bayesian model averaging. Additionally, by
consulting the literature, we identify TESS flare rates for 46 stars, optical
variability for 78 stars, and X-ray emission for 46 stars in our sample. We
discuss our catalog in the context of planet habitability and draw attention to
key gaps in our knowledge where precursor science can help to inform HWO
mission design trade studies in the near future. Notably, only 33 of the 164
stars in our sample have reliable space-based UV measurements, and only 40 have
a mid-IR measurement. We also find that phosphorus, a bio-essential element,
has only been measured in 11 of these stars, motivating future abundance
surveys. Our catalog is publicly available and we advocate for its use in
future studies of promising HWO targets.
