MOURARD , Denis

The principles of optical long baseline interferometry are presented firstly from the point of view of the coherence of the stellar wavefront and secondly from the point of view of the Object-Image relationship. These two complementary approaches permit to extract some important considerations for the actual implementation of this imaging...

International audience

We obtained spectro-interferometric observations in the visible of $\beta$~Lyrae and $\upsilon$~Sgr using the instrument VEGA of the CHARA interferometric array. For $\beta$~Lyrae, the dispersed fringe visibilities and differential phases were obtained in spectral regions containing the H$\alpha$ and HeI 6678 lines and the H$\beta$ and HeI 4921...

Context. To progress in the understanding of evolution of massive stars one needs to constrain the mass-loss and determine the phenomenon responsible for the ejection of matter an its reorganization in the circumstellar environment Aims. In order to test various mass-ejection processes, we probed the geometry and kinematics of the dust and gas...

International audience

International audience

With the aim of pushing the limiting magnitude of interferometric instruments, the need for wide-band detection channels and for a coordinated operation of different instruments has considerably grown in the field of long-baseline interferometry. For this reason, the Center for High Angular Resolution Astronomy (CHARA), an array of six...

Recent interferometric observations of the brightest and angularly largest classical Cepheid, l Carinae, with ESO's Very Large Telescope Interferometer have resolved with high precision the variation of its angular diameter with phase. We compare the measured angular diameter curve to the one that we derive by an application of the...

This paper summarizes the status, opportunities and some future policy initiatives relevant to future multi-wavelength/multi-messenger (MW/MM) astrophysics. This summary is considered timely given the ramp-up in facilities and widening exploration of physics across the electromagnetic spectrum and beyond.

International audience

International audience

International audience

International audience

International audience

International audience

In this paper we present the most promising science cases for a new generation visible instrument on the VLTI and the conceptual idea for the instrumental configuration. We also present a statistical study of the potential targets that may be accessible for the different classes of objects and for the required spectral resolutions.