A Uniform Set of DAV Atmospheric Parameters

We have observed over 150 hydrogen-atmosphere dominated, pulsating white dwarfs (DAVs) using the Goodman Spectrograph on the SOAR Telescope. This includes all known DAVs south of +10$^{\circ}$ declination as well as those observed by the {\em K2} mission. Because it employs a single instrument, our sample allows us to carefully explore systematics in the determination of atmospheric parameters, $T_{eff}$ and $\log{g}$. While some systematics show changes of up to 300 K in $T_{eff}$ and 0.06 in log(g), the relative position of each star in the $T_{eff}$-$\log{g}$ plane is more secure. These relative positions, combined with differences in pulsation spectra, will allow us to investigate relative differences in the structure and composition of over 150 DAVs through differential seismology.