A SPECTROSCOPIC STUDY OF THE LONG-PERIOD DWARF NOVA DX ANDROMEDAE

Wepresenttime-resolvedspectraofthedouble-lined dwarfnovaDX Andinquiescencefromtwocampaignsin1989 and 1993. Using an unusual method, we have reconstructed the radial velocity amplitudes and phases of the absorption and emission line components from data suffering from serious wavelength calibration problems by measuring the relative mo- tions of as well as the phase shift between the two line systems. We are thus able to refine the orbital period and to determine a long-term ephemeris. The relative contribution of the primary to the total light was measured as a function of wavelength, per- mitting to correct the absorption line spectrum for the veiling effect.Thesecondarystarexhibitsseveralspectralpeculiarities: in addition to the enhanced Ca I absorption lines reported pre- viously, we find several Cr I lines to be significantly stronger than in a comparison star of similar spectral type.