Spin-period variations in the intermediate polar RX J2133.7+5107

TL;DR

This study presents a 17-year photometric analysis of RX J2133.7+5107, revealing a very rapid white dwarf spin-up and detailed superhump period behavior, contributing to understanding of accretion dynamics in intermediate polars.

Contribution

The paper provides the most precise spin period measurement and identifies an exceptionally fast spin-up rate in RX J2133.7+5107, enhancing knowledge of white dwarf accretion processes.

Findings

White dwarf spin period is 570.811470 seconds.

The spin-up timescale is approximately 148,300 years.

Superhump period is refined to 0.280130 days.

Abstract

We report the results of long-term time series photometry on RX J2133.7+5107 (also known as 1RXS J213344.1+510725) obtained at several observatories. Using data taken during 17 years, we determined the current value of the spin period of $570.811470$ seconds with the formal accuracy of $0.000006$ seconds and a spin-up of the white dwarf with a characteristic time of $1.483(1)\times10^5$ years. This is even faster than that reported previously and, if confirmed, makes this object have one of the fastest spin-up timescales of all known intermediate polars. We derived an improved value of the superhump period of the system to be $0^d.280130(1)$. Superhump maxima timings are moving on the phase curve from season to season, showing non-monotonic changes, without a change in superhump period.