Analysis of the white--light flickering of the Intermediate Polar V709 Cas with wavelets and Hurst analysis

TL;DR

This paper analyzes the flickering behavior of the Intermediate Polar V709 Cas using wavelet and Hurst analysis, revealing self-similarity, persistent memory, and classification insights based on flickering properties.

Contribution

It introduces a method combining wavelet and Hurst analysis to characterize flickering in CVs, aiding in subtype classification especially when optical signatures are ambiguous.

Findings

Flickering exhibits self-similarity from tens of minutes to 10 seconds.

Alpha and Sigma are anticorrelated in flickering analysis.

V709 Cas falls in the magnetic system region of the alpha-Sigma diagram.

Abstract

We characterize the flickering observed in the optical lightcurve of the Intermediate Polar system V709 Cas by determining its position in the alpha-Sigma as in the Fritz and Bruch (1998) classification scheme. Sigma represents the strength of flickering at a given timescale, while alpha describes the energy distribution of the flickering at different time scales. Here alpha is independently obtained with both the wavelets and the Hurst R/S analysis. The flickering shows self-similarity in the time scale ranging from tens of minutes down to 10 seconds with stochastic persistent memory in time. alpha and Sigma appear anticorrelated. In the alpha-Sigma diagram V709 Cas falls in the region of magnetic systems. Since V709 Cas shows the spin period of the magnetic WD only in the X-ray but not in the optical, we conclude that this method can be used to characterize CV subtypes especially when their classification is uncertain.