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Asteroseismology of white dwarf stars provides important constraints on our models of stellar evolution and Galactic history. Recently, theoretical advances by Montgomery (2005) have allowed us to use stellar pulsations to probe the physics of convection through nonlinear light curve fitting. We have chosen R808 (mv=14.2) as our second target for XCOV26 for its importance to both asteroseismology and our understanding of convection across the DAV instability strip. R808 was discovered to be a pulsating DA white dwarf in 1976 (McGraw & Robinson 1976). It is a large amplitude, multiperiodic pulsator with an extremely nonlinear light curve (Figure 1), making it a perfect candidate for Montgomery's technique. With Teff=10300 K (Mullaly et al. 2007), it is also one of the coolest DAV pulsators, and offers the opportunity to study the characteristics of white dwarfs at the red edge of the DAV instability strip. However, despite its importance and its bright magnitude, this star has not been observed extensively since its discovery and little is known about its pulsation characteristics. Our first goal is to measure an accurate set of frequencies in this complex pulsator, and for this the coverage provided by the Whole Earth Telescope is essential. These frequencies will allow us to use asteroseismology to constrain its total mass, core composition, rotation rate, and the mass of its hydrogen surface layer. The hydrogen layer mass is determined in the highly uncertain final stages of mass loss, and in principle can range from 10-11 M* to $10-11 Mo. This layer plays an important role in the cooling of DA white dwarfs and such a large range can lead to uncertainties of up to a Gyr in the ages of the coolest white dwarfs. Our second, complementary goal is to determine R808's viability as a candidate for Montgomery's light curve fitting technique. We will examine the stability of the pulsations in phase and amplitude, resolve the multiplets, and attempt to assign l and m values to the modes in order to assess the suitability of R808 as a WET candidate. References: McGraw, J.T. & Robinson, E. L., 1976, ApJL, 205, L155 Montgomery, M. 2005, ApJ, 633, 1142 Mullaly, F. et al. 2007, ApJS, 206