Abstract

The SPHERE (Spectro-Polarimetric High-contrast Exoplanet Research) instrument aims at detecting extremely faint sources (giant extrasolar planets) in the vicinity of bright stars1. Such a challenging goal requires the use of a very-high-order performance Adaptive Optics [AO] system feeding the scientific instruments with a quasi-perfect flat wave front corrected from all the atmospheric turbulence and internal defects. This AO system, called SAXO (Sphere Ao for eXoplanet Observation) is the heart of the instrument, a heart beating 1200 time per second and providing unprecedented image quality for a large ground based telescope at optical/near infrared wavelength. We will present the latest results obtained on-sky, demonstrating its exceptional performance (in terms of correction quality, stability and robustness) and tremendous potentiality for high contrast imaging and more specifically for exoplanet discovery.

Highlights

  • Direct detection and spectral characterization of exoplanets is one of the most exciting and one of the most challenging areas in the current astronomy

  • We have proposed ZELDA [23,24,25,26] as a concept based on the Zernike phase contrast applied to the measurements of quasi-static aberrations in exoplanet direct imaging instruments

  • In Dec. 2015, we performed tests that led to the experimental validation of our concept [27 and this conference]. These first results show that calibration of NCPA using ZELDA can significantly reduce the residual speckle brightness in coronagraphic images for exoplanet observation, see Figure 17 We have used ZELDA as a diagnostic tool to understand the origin of the unforeseen low-wind effect [28 and this conference], see Section 5.1. 5.3 Dark hole with SPHERE The SPHERE instrument has been used as an experimental test bench to perform some validation of techniques dedicated to very high contrast

Read more

Summary

INTRODUCTION

Direct detection and spectral characterization of exoplanets is one of the most exciting and one of the most challenging areas in the current astronomy. The three scientific channels gather complementary instrumentation to maximize the probability of exoplanet detection and to give us access to a large range of wavelengths and information (e.g., imaging, spectra, and polarization7) SAXO measures and corrects any wave-front perturbation (rapidly varying turbulence or quasi-static instrumental speckles [8]) in order to ensure an unprecedented image quality on ground -based telescope. It gathers some of the most worldwide advanced components and AO concepts. This corresponds to a world record for monolithic telescope either on the ground or in space

SOME SAXO SPECIFIC FEATURES
Low flux behavior
The main SPHERE limitation
SOME UNIQUE SPHERE FEATURES ILLUSTRATED ON SCIENTIFIC IMAGES
Findings
CONCLUSION
Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.