SPECTROSCOPY OF THE CATACLYSMIC VARIABLE UU AQUARTII - S-WAVES AND BRIGHT SPOTS

This paper reports the results of UV and optical spectroscopy of the n ova-like variable UV Aqr. There is a decrease in the light flux of bot h the optical and UV emission lines at phase similar to 0.95. This app ears to be due to an occultation of an asymmetric accretion disk. The emission-line profiles seem to show the first half of the rotational d isturbance of the disk eclipse. There is a secondary eclipse at phase 0.4 in the optical continuum and the hydrogen emission lines. It is no t present in the UV continuum or emission lines. This eclipse occurs w hen the bright spot is at superior conjunction. This raises the possib ility that this is an occultation of the bright spot/s-wave region by material suspended above the central disk. The accretion disk emission in the Doppler tomogram of the HP emission line was used to obtain th e radial velocity amplitude of the white dwarf star. The mass ratio wa s estimated by matching the s-wave position with stream trajectories. The results were significantly different from that of Baptista et al. These authors used the eclipse phasing of the continuum hot spot and t he assumption that the hot spot is located on the stream trajectory. T he reasons for this discrepancy are unclear.