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MACAO stands for Multi Application Curvature Adaptive Optics. A similar concept is applied to fulfill the need for wavefront correction for several VLT instruments. MACAO-VLTI is one of these built in 4 copies in order to equip the Coude focii of the ESO VLT's. The optical beams will then be corrected before interferometric recombination in the VLTI (Very Large Telescope Interferometer) laboratory. MACAO-VLTI uses a 60 elements bimorph mirror and curvature wavefront sensor. A custom made board processes the signals provided by the wavefront detectors, 60 Avalanche Photo-diodes, and transfer them to a commercial Power PC CPU board for Real Time Calculation. Mirrors Commands are sent to a High Voltage amplifier unit through an optical fiber link. The tip-tilt correction is done by a dedicated Tip-tilt mount holding the deformable mirror. The whole wavefront is located at the Coude focus. Software is developed in house and is ESO compatible. Expected performance is a Strehl ratio sligthly under 60% at 2.2 micron for bright reference sources (star V<10) and a limiting magnitude of 17.5 (Strehl ~0.1). The four systems will be installed in Paranal successively, the first one being planned for June 2003 and the last one for June 2004.

Abstract. The detection of faint emissions very close to much brighter objects is required in several different fields of astrophysics, for example in the search for planetary disks. We present here a coronograph that we built to work with come-on-plus, the ESO adaptive optics system, high angular resolution being of key importance in allowing observations close to a central, occulted object. The first results are presented and analyzed in order to establish the performance of this instrument in terms of contrast and detectability of faint emissions close to a central star.

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