Time-frequency analysis of three strongly variable Wolf-Rayet stars: WR 6, WR 134, and WR 123

摘要

We apply the technique of time-frequency analysis to look for temporal changes in the variability power spectrum of the three strongly variable Wolf-Rayet stars, WR 6, WR 134, and WR 123, for which relatively long strings of homogeneous photometry are available. The observed changes of the power spectra may be related to the gradual restructuring of the stellar wind in the presence of "active" regions and/or nonradial pulsations or, in the case of the long-term variability of WR 134, caused by the presence of a low-mass companion.