  We use the irradiated secondary star in the remnant of Nova Cyg 1975 as a
probe of the cooling white dwarf. At superior conjunction the flux in the B
band is dominated by the irradiated face of the secondary star. The heated face
produces an orbital modulation which is dependent on the strength of the
irradiating source. We demonstrate that the cooling rate of the white dwarf is
consistent with the theoretical model of Prialnik (1986).
