The Four‐Quadrant Phase Mask Coronagraph. IV. First Light at the Very Large Telescope

We present the first high-contrast images obtained at the ESO Very Large Telescope using a four-quadrant phase mask coronagraph. The two-night commissioning was carried out in 2004 January on NACO, the near-IR camera with adaptive optics at UT4. We evaluated the behavior of the coronagraph on a variety of astrophysical targets: binary stars, circumstellar disks, and active galactic nuclei. The performance of the coronagraph is in agreement with our expectations based on numerical simulations. The phase mask provides a stellar peak attenuation of a factor of about 10 on average (for long exposure), and its performance is limited only by the phase residuals (mainly low-order aberrations) that are left uncorrected by the adaptive optics system.

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