Evolutionary state of low-accretion-rate polar binaries

Determine whether low-accretion-rate polar systems with weak Hα emission are detached binaries or semi-detached cataclysmic variables undergoing exceptionally low accretion rates.

Background

The authors identify a group of apparently single magnetic white dwarfs whose weak, variable Hα emission reveals close binary companions. Although the systems share properties suggestive of extremely low accretion, their detached or semi-detached evolutionary status remains disputed.

References

As with the cyclotron systems above, there remains some ongoing discussion around whether these systems are detached or semi-detached CVs that simply have very low accretion rates, with the latter option being favoured \citep{MunozGiraldo2023}.

— The DESI Data Release 1 white dwarf catalogue  (2609.04314 - Swan et al., 3 Sep 2026) in Section 5.8.3, Low-accretion-rate polars