Characterization of variable stars by robust wave variograms: An application to Hipparcos mission

Variogram analysis is applied to time series of variable stars. This method allows to characterize timescales of varying signals. It is well suited fo r periodic and pseudo-periodic signals. The aspects of robustness, bin posi tions and bin widths for the variogram estimator are assessed, evaluated wi th the help of simulations and adapted to the Hipparcos photometry. For ins tance variogram methodology is successfully applied for the detection of sp urious periods, the estimation of measurement noise and the analysis of the pseudo-period of some typical Hipparcos variable stars.