Bradley E. Schaefer
Abstract Recurrent nova (RN) T Pyxidis (T Pyx) has a complex history of mass accreting onto and ejection from the white dwarf, with a classical nova eruption around 1866 kick-starting an RN-phase with six RN eruptions from 1890–2011. T Pyx is a primary progenitor candidate for Type Ia supernovae (SN Ia). This is chiefly a question of whether the mass accreted by the white dwarf ( M accreted ) is more or less than the mass ejected by the nova eruptions ( M ejecta ) over the entire eruption cycle. Prior attempts to measure M ejecta from the traditional methods have a scatter of >130×, so only a new technique can provide a measure of adequate accuracy and reliability. This new technique is the timing experiment of measuring the orbital period from 1986–2025, where the period increased by +50.3 ± 7.9 ppm across the 2011 eruption. With simple and sure physics, the best estimate for the mass ejected by one RN event is >2400 × 10 −7 M ⊙ , with an extreme inviolate limit of ≫354 × 10 −7 M ⊙ . Over all eruptions in a cycle, M ejecta >17120 × 10 −7 M ⊙ , with an inviolate limit of M ejecta ≫2144 × 10 −7 M ⊙ . Over the full eruption cycle, the white dwarf accreted 220 × 10 −7 M ⊙ . So, M ejecta ≫11.3 × M accreted , and T Pyx can never become an SN Ia. This paper is the seventh in a series proving that each of various popular candidate SN Ia progenitors cannot possibly evolve to a supernova, including V445 Pup, U Sco, T CrB, all symbiotic stars, FQ Cir, V1405 Cas, and now T Pyx.