LOPEZ , Bruno

International audience

International audience

We present the results of observations of the SiO masers at 7 mm wavelength in several oxygen rich Asymptotic Giant Branch (AGB) stars. These observations were coordinated with observations using the ESO VLTI/MIDI interferometer at 10 mum wavelength. These stars are o Ceti (Mira), U Herculis (U Her), OH26.5+0.6, R Leonis (R Leo), and W Hydrae...

The color-differential astrometry method consists in measuring the variations of the photocenter position with wavelength. This yields spectral information on the spatial structure of an unresolved source, and could allow, among other applications, the direct detection and spectroscopy of extrasolar planets. We give some estimates of...

We present the current performances of the AMBER / VLTI instrument in terms of differential observables (differential phase and differential visibility) and show that we are already able to reach a sufficient precision for very low mass companions spectroscopy and mass characterization. We perform some extrapolations with the knowledge of the...

Nous présentons de nouveaux éléments orbitaux pour l'étoile double visuelle WDS~02193-0259 (JOY~1~Aa ADS~1778). Ces éléments ont été obtenus en utilisant les dernières mesures que nous avons effectuées avec le tavelographe PISCO et le télescope Bernard Lyot de 2 m du Pic du Midi, et celles déjà disponibles dans la littérature.

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Asteroseismology aims at constraining the stellar evolution theory, and allows to determine the age of stars together with other fundamental parameters. We present recent results obtained by interferometry, and prospects for the future.

This paper presents speckle observations of Mira (o Cet) and late-type stars with the PISCO speckle camera of Pic du Midi during the period 1995-1998. A survey for binarity among a sample of late-type stars was performed, which led to 7 positive detections out of 36 objects. Photometric and color variations of the companion of Mira were...