On the origin of the peculiar cataclysmic variable AE Aquarii

TL;DR

This paper proposes a scenario where AE Aquarii's rapid white dwarf spin resulted from intense past accretion, leading to magnetic field screening and eventual transition to an ejector state, linking it to the evolution of Polars and recycled pulsars.

Contribution

It introduces a new evolutionary model explaining AE Aquarii's peculiar properties through magnetic screening and spin-up processes.

Findings

High accretion rates caused temporary magnetic screening.

The white dwarf was spun up to 33 seconds during accretion.

AE Aquarii is a transitional object linking Polars and recycled pulsars.

Abstract

The nova-like variable AE Aquarii is a close binary system containing a red dwarf and a magnetized white dwarf rotating with the period of 33 seconds. A short spin period of the white dwarf is caused by an intensive mass exchange between the system components during a previous epoch. We show that a high rate of disk accretion onto the white dwarf surface resulted in temporary screening of its magnetic field and spin-up of the white dwarf to its present spin period. Transition of the white dwarf to the ejector state occurred at a final stage of the spin-up epoch after its magnetic field had emerged from the accreted plasma due to diffusion. In the frame of this scenario AE Aqr represents a missing link in the chain of Polars evolution and the white dwarf resembles a recycled pulsar.