25 research outputs found

    SPHERE: the exoplanet imager for the Very Large Telescope

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    Observations of circumstellar environments to look for the direct signal of exoplanets and the scattered light from disks has significant instrumental implications. In the past 15 years, major developments in adaptive optics, coronagraphy, optical manufacturing, wavefront sensing and data processing, together with a consistent global system analysis have enabled a new generation of high-contrast imagers and spectrographs on large ground-based telescopes with much better performance. One of the most productive is the Spectro-Polarimetic High contrast imager for Exoplanets REsearch (SPHERE) designed and built for the ESO Very Large Telescope (VLT) in Chile. SPHERE includes an extreme adaptive optics system, a highly stable common path interface, several types of coronagraphs and three science instruments. Two of them, the Integral Field Spectrograph (IFS) and the Infra-Red Dual-band Imager and Spectrograph (IRDIS), are designed to efficiently cover the near-infrared (NIR) range in a single observation for efficient young planet search. The third one, ZIMPOL, is designed for visible (VIR) polarimetric observation to look for the reflected light of exoplanets and the light scattered by debris disks. This suite of three science instruments enables to study circumstellar environments at unprecedented angular resolution both in the visible and the near-infrared. In this work, we present the complete instrument and its on-sky performance after 4 years of operations at the VLT.Comment: Final version accepted for publication in A&

    Installation and commissioning of FLAMES, the VLT Multifibre Facility

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    International audienceFLAMES (Fibre Large Array Multi Element Spectrograph) is the VLT Fibre Facility, installed and commissioned at the Nasmyth A focus of UT2 (Kueyen Telescope). FLAMES was built and assembled in about four years through an international collaboration between ten institutes in six countries and three continents. It had first light with the fibre link to the red arm of UVES on April 1, and with the GIRAFFE spectrograph on July 3. We report here on the complex process of integration and commissioning, and we compare the expected and observed astronomical requirements

    CANARY: The NGS/LGS MOAO demonstrator for EAGLE

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    International audienceEAGLE is a multi-object 3D spectroscopy instrument currently under design for the 42-metre European Extremely Large Telescope (E-ELT). EAGLE will use open-loop Multi-Object Adaptive Optics (MOAO) to provide partial AO correction across a wide (5-10 arcmin) field of view. The novelty of this scheme is such that on-sky demonstration is required prior to final construction of an E-ELT instrument. The CANARY project will implement a single channel of an MOAO system on the 4.2m William Herschel Telescope. The CANARY project is undergoing a phased development plan that starts with demonstration of low-order open-loop AO correction using first NGS then Rayleigh LGS tomography, moving to a demonstration of high-order open-loop AO correction using LGS tomography. This final stage will also include 2 DMs in a woofer-tweeter configuration similar to that of EAGLE when installed at the E-ELT. We describe the requirements for the various phases of MOAO demonstration, the corresponding CANARY configurations and capabilities and the current designs of the various subsystems
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