L'-band AGPM vector vortex coronagraph's first light on VLT/NACO: Discovery of a late-type companion at two beamwidths from an F0V star

摘要: Context. High contrast imaging has thoroughly combed through the limited search space accessible with first-generation ground-based adaptive optics instruments and Hubble Space Telescope. Only a few objects were discovered, many non-detections reported statistically interpreted. The field is now in need of technological breakthrough. Aim. Our aim to open new systems such as NACO at Very Large Telescope, by providing ground-breaking inner working angle (IWA) capabilities L' band. band sweet spot for high coronagraphy since planet-to-star brightness ratio favorable, while Strehl naturally higher. Methods. An annular groove phase mask (AGPM) vector vortex coronagraph optimized band, made from diamond subwavelength gratings was manufactured qualified lab. AGPM enables very small IWA, potentially being key unexplored discovery space. Results. Here we present installation successful on-sky tests an L'-band on NACO. Using angular differential imaging, which well suited rotational symmetry AGPM, demonstrated \Delta > 7.5 mag IWA ~ 0".09 onwards, during average seeing conditions, total integration times hundred seconds.