Dwarf Novae with Newly Determined Parallaxes: Model Analyses of VY Aquarii, RU Pegasi, and T Leonis

Abstract

Using newly determined parallaxes for dwarf novae, we have derived outburst accretion rates for VY Aqr, RU Peg, and T Leo, and for T Leo during quiescence. The two short-period dwarf novae, VY Aqr and T Leo, show good agreement with optically thick steady-state accretion disks in outburst, whereas RU Peg shows a significant departure from a steady-state disk. We have determined that the white dwarf in T Leo has Teff=16,000+/-1000 K, a value consistent with long-term compressional heating when gravitational-wave emission drives mass transfer. The white dwarf in T Leo has a temperature in the same narrow range as other WZ Sge-like dwarf novae.