Orbital Period Changes of Recurrent Nova T Pyxidis Demonstrate that M_ejecta >> 11.3xM_accreted and Is Not a Type Ia Supernova Progenitor

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 a RN-phase with six RN eruptions from 1890--2011. T Pyx is a primary progenitor candidate for Type Ia supernovae (SNIa). This is chiefly a question of whether the mass accreted by the white dwarf ($M_{\mathrm{accreted}}$) is more-or-less than the mass ejected by the nova eruptions ($M_{\mathrm{ejecta}}$) over the entire eruption cycle. Prior attempts to measure $M_{\mathrm{ejecta}}$ from the traditional methods have a scatter of $>$130$\times$, 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 to 2025, where the period increased by $+$50.3$\pm$7.9 parts-per-million across the 2011 eruption. With simple and sure physics, the best estimate for the mass ejected by one RN event is $>$2400$\times$10${}^{-7}$ M${}_{\odot }$, with an extreme inviolate limit of $\gg$354$\times$10${}^{-7}$ M${}_{\odot }$. Over all eruptions in a cycle, $M_{ejecta}$$>$17120$\times$10${}^{-7}$ M${}_{\odot }$, with an inviolate limit of $M_{ejecta}$$\gg$2144$\times$10${}^{-7}$ M${}_{\odot }$. Over the full eruption cycle, the white dwarf accreted 220$\times$10${}^{-7}$ M${}_{\odot }$. So M${}_{\mathrm{ejecta}}$$\gg$11.3$\times$M${}_{\mathrm{accreted}}$, and T Pyx can never become a SNIa. This paper is the seventh in a series proving that each of various popular candidate SNIa 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.

7th in a series of ApJ papers, each proving that popular progenitor candidates cannot become Type Ia supernovae: 1. V445 Pup (arXiv:2412.17286), 2. T CrB (arXiv:2510.01587), 3. U Sco (arXiv:2510.01589), 4. FQ Cir (arXiv:2511.16594), 5. all symbiotic stars (arXiv:2511.19948), 6. V1405 Cas (ApJ submitted), 7. T Pyx (ApJ in press)