EDP Sciences
Free access
Volume 502, Number 1, July IV 2009
Page(s) 1 - 5
Section Astrophysical processes
DOI http://dx.doi.org/10.1051/0004-6361/200911656
Published online 04 June 2009
A&A 502, 1-5 (2009)
DOI: 10.1051/0004-6361/200911656

Analysis of the white-light flickering of the intermediate polar V709 Cassiopeiae with wavelets and Hurst analysis

F. Tamburini1, D. de Martino2, and A. Bianchini1

1  Department of Astronomy, University of Padova, vicolo dell' Osservatorio 3, 35122, Padova, Italy
    e-mail: fabrizio.tamburini@unipd.it
2  INAF–Astronomical Observatory of Capodimonte, Moiarello 16, 80131, Naples, Italy

Received 13 January 2009 / Accepted 12 April 2009

We characterize the flickering observed in the optical light curve of the intermediate polar system V709 Cas by determining its position in the $\alpha$-$\Sigma$ diagram of Fritz and Bruch classification scheme. The strength of flickering on a given timescale is represented by $\Sigma$, while $\alpha$ is the energy distribution of the flickering at different timescales. Here $\alpha$ is derived independently with both the wavelets and the Hurst R/S analysis. The flickering shows self-similarity on a timescale ranging from tens of minutes down to 10 s with stochastic persistent memory in time. The parameters $\alpha$ and $\Sigma$ appear to be anticorrelated. In the $\alpha$-$\Sigma$ diagram, V709 Cas occupies 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.

Key words: stars: binaries: close -- accretion, accretion disks -- chaos

© ESO 2009