THE DISCOVERY OF STRONG NEUTRAL ATOMIC CARBON ABSORPTION-LINES IN THE SPECTRUM OF THE DAQZ5 WHITE-DWARF IN THE ULTRA SHORT-PERIOD DWARF NOVA WZ SAGITTAE DURING QUIESCENCE

We report the identification of strong neutral carbon absorption features in the photosphere of the white dwarf exposed during the quiescent state of the ultra-short-period dwarf nova WZ Sagittae. On the basis of its carbon in a hydrogen-dominated photosphere with Si II also present, we assign the white dwarf in WZ Sge the spectroscopic classification DAQZ5, compare its line spectrum with other (single) white dwarfs containing photospheric carbon, and briefly discuss the possible implications of our line identifications for accretion physics, convective dredge-up, mixing, and dilution and diffusion theory.