The asynchronous polar V1432 Aquilae and its path back to synchronism

TL;DR

This study tracks the 15-year observational campaign of the unique asynchronous polar V1432 Aquilae, revealing its gradual return to synchronism and providing detailed data to test physical models of such systems.

Contribution

It offers the first long-term observational evidence of a polar returning to synchronism after a nova explosion, with detailed light emission patterns and eclipse timing analysis.

Findings

White dwarf is gradually catching up to orbital period

Eclipses serve as precise clocks for timing changes

Accretion stream patterns are complex and evolving

Abstract

V1432 Aquilae is the only known eclipsing asynchronous polar. In this respect it is unique and therefore merits our attention. We report the results of a 15-year campaign by the globally distributed Center for Backyard Astrophysics to observe V1432 Aql and investigate its return to synchronism. Originally knocked out of synchrony by a nova explosion before observing records began, the magnetic white dwarf in V1432 Aql is currently rotating slower than the orbital period but is gradually catching up. The fortuitously high inclination of the binary orbit affords us the bonus of eclipses providing a regular clock against which these temporal changes can be assessed. At the present rate, synchronism should be achieved around 2100. The continually changing trajectory of the accretion stream as it follows the magnetic field lines of the rotating white dwarf produces a complex pattern of light emission which we have measured and documented, providing comprehensive observational evidence against which physical models of the system can be tested.