Assisted stellar suicide: the wind-driven evolution of the recurrent nova T Pyxidis

We show that the extremely high luminosity of the short-period recurrent no va T Pyx in quiescence can be understood if this system is a wind-driven su persoft x-ray source (SSS). In this scenario, a strong, radiation-induced w ind is excited from the secondary star and accelerates the binary evolution . The accretion rate is therefore much higher than in an ordinary cataclysm ic binary at the same orbital period, as is the luminosity of the white dwa rf primary. In the steady state, the enhanced luminosity is just sufficient to maintain the wind from the secondary. The accretion rate and luminosity predicted by the wind-driven model for T Pyx are in good agreement with th e observational evidence. X-ray observations with Chandra or XMM may be abl e to confirm T Pyx's status as a SSS. T Pyx's lifetime in the wind-driven state is on the order of a million year s. Its ultimate fate is not certain, but the system may very well end up de stroying itself, either via the complete evaporation of the secondary star, or in a Type Ia supernova if the white dwarf reaches the Chandrasekhar lim it. Thus either the primary, the secondary, or both may currently be commit ting assisted stellar suicide.