High Contrast Imaging in the Visible: First Experimental Results at the Large Binocular Telescope

TL;DR

This paper reports the first on-sky results of the SHARK-VIS high contrast imager at the Large Binocular Telescope, demonstrating excellent adaptive optics performance and achieving high contrast imaging at visible wavelengths.

Contribution

It presents the first experimental results of a visible-wavelength high contrast imager at LBT, showcasing the system's capabilities and contrast performance using innovative data analysis techniques.

Findings

Achieved contrast of 5×10⁻⁵ at 630 nm beyond 100 mas

Demonstrated high spatial resolution and contrast with LBT ExAO system

Validated the effectiveness of synthetic object injection and ADI for contrast assessment

Abstract

In February 2014, the SHARK-VIS (System for High contrast And coronography from R to K at VISual bands) Forerunner, a high contrast experimental imager operating at visible wavelengths, was installed at LBT (Large Binocular Telescope). Here we report on the first results obtained by recent on-sky tests. These results show the extremely good performance of the LBT ExAO (Extreme Adaptive Optics) system at visible wavelengths, both in terms of spatial resolution and contrast achieved. Similarly to what was done by (Amara et al. 2012), we used the SHARK-VIS Forerunner data to quantitatively assess the contrast enhancement. This is done by injecting several different synthetic faint objects in the acquired data and applying the ADI (angular differential imaging) technique. A contrast of the order of $5 \times 10^{-5}$ is obtained at 630 nm for angular separations from the star larger than 100 mas. These results are discussed in light of the future development of SHARK-VIS and compared to those obtained by other high contrast imagers operating at similar wavelengths.