Dwarf novae in outburst : simultaneous ultraolet and optical observations of UZ Serpentis, RX Andromedae and AH Herculis.
Verbunt, F.; Schwarzenberg-Czerny, A.; Jones, D. H. P.; Pringle, J. E.; Wade, R. A.; Echevarria, J.; Argyle, R. W.; La Dous, C.; Schoembs, R.
United Kingdom, Netherlands, Poland, Germany
Abstract
The authors present spectroscopic and photometric observations in the optical and ultraviolet wavelength regions made during outbursts of the three dwarf novae UZ Serpentis, RX Andromedae and AH Herculis. The observations do not cover the rapid initial rise to outburst, but rather the peak and the subsequent decline. The overall changes of the continuum distributions are different in the three objects, and for UZ Ser the authors present evidence that the distribution repeats from outburst to outburst, although the line strengths do not. The decline from outburst is characterized by a drop in flux at all wavelengths, the drop being faster at shorter wavelengths. The spectrum of RX And observed at the decline is similar to that taken by Klare et al. at the same optical brightness but during a prolonged standstill.