COUDÉ DU FORESTO , Vincent

Analysis of the first interferometric fringes recorded at Dome C, Antarctica are presented. Measurements were taken 31 January and 1 February 2005 during daytime. Our purpose in performing the analysis was to measure temporal fluctuations of the atmospheric piston, which are critical for interferometers, and determine their sensitivity. These...

Context: Alpha Centauri is our closest stellar neighbor, at a distance of only 1.3 pc, and its two main components have spectral types comparable to the Sun. This is therefore a favorable target for an imaging search for extrasolar planets. Moreover, indications exist that the gravitational mass of Alpha Cen B is higher than its modeled mass,...

Context: Alpha Centauri is our closest stellar neighbor, at a distance of only 1.3 pc, and its two main components have spectral types comparable to the Sun. This is therefore a favorable target for an imaging search for extrasolar planets. Moreover, indications exist that the gravitational mass of Alpha Cen B is higher than its modeled mass,...

Recently available near-infrared interferometric data on late-type stars show a strong increase of diameter for asymptotic giant branch (AGB) stars between the K (2.0{-}2.4 mum) and L (3.4{-}4.1 mum) bands. Aiming at an explanation of these findings, we chose the objects alpha Orionis (Betelgeuse), SW Virginis, and R Leonis, which are of...

We report in this paper the direct interferometric measurement of the angular diameter of five nearby Vega-like stars: alpha PsA, beta Leo, beta Pic, ε Eri and tau Cet. The near-infrared (K and H bands) observations were conducted at the VLTI during the commissioning period with the VINCI instrument and three different baselines ranging from 66...

Recent site seeing testing campaigns conducted by our team from University of Nice1 show that Dome C represents the best site on Earth for astronomical high angular resolution (HAR) observations at optical and IR wavelengths. The dramatic gain over relevant HAR parameters r0, L0, θ0 and τ0, added to very low temperatures during the polar winter...

The PERSEE breadboard, developed by a consortium including CNES, IAS, LESIA, OCA, ONERA and TAS since 2005, is a nulling demonstrator that couples an infrared nulling interferometer with a formation flying simulator able to introduce realistic disturbances in the set-up. The general idea is to prove that an adequate optical design can...

This article reviews the situation for robotization of telescopes and instruments at the Antarctic station Concordia on Dome C. A brain-storming meeting was held in Tenerife in March 2007 from which this review emerged. We describe and summarize the challenges for night-time operations of various astronomical experiments at conditions ``between...