Ultraviolet observations of the long-period dwarf nova DX And in outburst

Ultraviolet observations of the little-studied dwarf nova, DX And, are presented. The observations were made with the International Ultraviolet Explorer satellite (IUE) during the late stages of a rise to outburst maximum in 1989 November. The spectra indicate a low orbital inclination angle and show clear signs of substantial interstellar reddening |$[E(B-V) = 0.20 \pm 0.04]$|⁠. The wind-dominated N Vλ1240 and C IV 1549 profiles show significant velocity-shifting within our time series of spectra. If these motions are linked with the binary orbit, an estimate of 11 hr is obtained for the orbital period. Fitting of the C IV and N v absorption profiles provides a lower limit to the mass loss rate of a few times |$10^{-11} \enspace M_\odot \enspace \text {yr}^{-1}$|⁠. It is argued that the ionization state of DX And's wind is most probably higher than usual or, failing that, the nitrogen abundance in the accreting material is enhanced.