Speckle observations of binary systems measured by Hipparcos ^*

¹ UMR 5572 d'Astrophysique, Observatoire Midi-Pyrénées -CNRS, 14 avenue Édouard Belin, 31400 Toulouse, France
² UMR 6091, Observatoire de Besançon -CNRS, 41bis avenue de l'Observatoire, 25010 Besançon, France
³ Koninklijke Sterrenwacht van België, Ringlaan 3, 1180 Brussel, België
⁴ Cracow Observatory, Jagiellonian University, 171 ulica Orla, 30244 Krakow, Poland
⁵ UMR 6525 Astrophysique, Université de Nice Sophia-Antipolis -CNRS, Valrose, 06108 Nice Cedex 2, France

Corresponding author: J.-L. Prieur, prieur@ast.abs-mip.fr

Received: 5 June 2000
Accepted: 5 December 2000

Abstract

From speckle observations made with the PISCO speckle camera at the Pic du Midi Observatory, we present high angular resolution astrometric data for 43 binary stars already observed by the Hipparcos satellite. This sample consists of mainly new Hipparcos eclipsing binaries with a visual companion closer than one arcsecond, chosen with the aim to study the dynamical implications of a third component on the observational parameters of the eclipsing system. In addition, we also included a selection of close visual binaries with few speckle data in order to analyse possible systematic departures between the speckle and the non-speckle orbits. The reduction method and the results are presented in detail. For the close visual binaries we confront our observations with the ephemerides based on the best known orbits. For the wide visual binaries the confrontation is made directly with the Hipparcos data. Our observations are consistent both with previous speckle data and with most of the Hipparcos measurements.