Far Ultraviolet Spectral Analysis of the Prototype Nova-Like Variable VY Sculptoris from the High State to the Low State

Abstract

The prototype nova-like variable VY Sculptoris was observed by the IUE during four different optical brightness states of the system. The FUV flux level from the highest state to the lowest state declines by a factor of 28. We have carried out model accretion disk and white dwarf atmosphere fitting to the spectra. The corresponding accretion rates range from $\dot{M}= 8 \times 10^{-9}$M$_{\sun}$ yr$^{-1}$ at the highest FUV flux level down to $\dot{M}= 1.9\times 10^{-10}$M$_{\sun}$ yr$^{-1}$ at the lowest flux level. We report tentative evidence for the detection of the underlying white dwarf with $T_{\rm eff} = 45,000$K in the spectrum with the lowest flux level.