Can dwarf novae produce type Ia supernovae?

¹ Yunnan Observatories, Chinese Academy of Sciences (CAS), Kunming 650216, China
² International Centre of Supernovae, Yunnan Key Laboratory, Kunming 650216, China
³ University of Chinese Academy of Sciences, Beijing 100049, China
⁴ Center for Astronomical Mega-Science, Chinese Academy of Sciences, Beijing 100012, China

^★ Corresponding authors: This email address is being protected from spambots. You need JavaScript enabled to view it. ; This email address is being protected from spambots. You need JavaScript enabled to view it.

Received: 7 January 2026
Accepted: 19 June 2026

Abstract

Context. Accreting white dwarfs (WDs) are considered some of the most promising progenitor candidates of type Ia supernovae (SNe Ia). Dwarf novae (DNe), a subclass of cataclysmic variables, consist of a CO WD accretor and a low-mass donor star, which can be either a main-sequence (MS) star or a slightly evolved subgiant. Previous studies suggested that, under the thermal–viscous disc instability mechanism, the time-averaged accretion rate in long-period DNe approaches the regime of stable hydrogen burning, potentially allowing WD mass growth towards the Chandrasekhar mass (M_Ch). However, whether such periodic accretion can sustain stable H burning and lead to a mass increase in the WD remains uncertain.

Aims. We explore whether high accretion rates on short, periodic timescales can maintain stable H burning on the WD surface and drive its growth towards M_Ch.

Methods. We investigated the mass retention efficiency of WDs undergoing intermittent, DN-like accretion using MESA simulations, and explored the dependence on the duty cycle, accretion rate, and initial WD properties.

Results. We find that periodic accretion fails to maintain stable H burning. During quiescent phases, the WD cools and becomes increasingly degenerate, triggering nova outbursts with declining mass retention efficiency, ultimately preventing further WD mass growth. We therefore suggest that DNe are unlikely to be progenitors of SNe Ia.