Astron. Astrophys. Suppl. Ser. 136, 421-428

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

L. Eyer^1,2 and M.G. Genton³

Send offprint request: L. Eyer

¹Instituut voor Sterrenkunde, Katholieke Universiteit Leuven, Celestijnenlaan 200 B, B-3001 Leuven, Belgium
²Observatoire de Genève, CH-1290 Sauverny, Switzerland
³Department of Mathematics, Massachusetts Institute of Technology, Cambridge, MA 02139-4307, U.S.A.

Received August 6, 1998; accepted January 21, 1999

Abstract:

Variogram analysis is applied to time series of variable stars. This method allows to characterize time-scales of varying signals. It is well suited for periodic and pseudo-periodic signals. The aspects of robustness, bin positions and bin widths for the variogram estimator are assessed, evaluated with the help of simulations and adapted to the Hipparcos photometry. For instance variogram methodology is successfully applied for the detection of spurious periods, the estimation of measurement noise and the analysis of the pseudo-period of some typical Hipparcos variable stars.

Key words: methods: data analysis -- methods: statistical -- stars: variables: general -- techniques: photometric