  We show that the UV spectrum (1280-3200 A) of the "superficially normal"
A-star Vega, as observed by the IUE satellite at a resolution comparable to the
star's rotational broadening width, can be fit remarkably well by a
single-temperature synthetic spectrum based on LTE atmosphere models and a
newly constructed UV line list. If Vega were a normal, equator-on,
slow-rotating star, then its spectrum and our analysis would indicate a
temperature of Teff ~ 9550 K, surface gravity of log g ~ 3.7, general surface
metallicity of [m/H] ~ -0.5, and a microturbulence velocity of v(turb) ~ 2.0
km/s. Given its rapid rotation and nearly pole-on orientation, however, these
parameters must be regarded as representing averages across the observed
hemisphere. Modeling the complex UV line spectrum has allowed us to determine
the specific surface abundances for 17 different chemical elements, including
CNO, the light metals, and the iron group elements. The resultant abundance
pattern agrees in general with previous results, although there is considerable
scatter in the literature. Despite its peculiarities, Vega has turned out to
provide a powerful test of the extent of our abilities to model the atmospheric
properties of the early A-stars, particularly the detailed UV line spectrum.
The value of the measurements from this pilot study will increase as this
analysis is extended to more objects in the rich high-dispersion IUE data
archive, including both normal and peculiar objects.
