Imaging binary stars by the cross-correlation technique^*

UMR 6525 Astrophysique, Université de Nice Sophia – Antipolis – Centre National de la Recherche Scientifique, Parc Valrose, F-06108 Nice Cedex 2, France

Send offprint request to: E. Aristidi

Received: 2 January 1997
Accepted: 25 March 1997

Abstract

We present in this paper a technique for imaging binary stars from speckle data. This technique is based upon the computation of the cross-correlation between the speckle frames and their square. This may be considered as a simple, easy to implement, complementary computation to the autocorrelation function of Labeyrie's technique for a rapid determination of the position angle of binary systems. Angular separation, absolute position angle and relative photometry of binary stars can be derived from this technique. We show an application to the bright double star ζ Sge observed at the 2 m Telescope Bernard Lyot.