Hi-5: a potential high-contrast thermal near-infrared imager for the VLTI

TL;DR

Hi-5 is a proposed high-contrast infrared imager for the VLTI aimed at characterizing exoplanets, dust, and other astrophysical phenomena in the thermal near-infrared, with technological advancements to improve contrast and science capabilities.

Contribution

The paper presents an update on the Hi-5 project, highlighting new technological pathways like integrated optics and fringe tracking for enhanced contrast in thermal near-infrared imaging.

Findings

Potential to characterize young exoplanets and exozodiacal dust.

Use of integrated optics in thermal near-infrared bands.

Enhanced contrast strategies for VLTI imaging.

Abstract

Hi-5 is a high-contrast (or high dynamic range) infrared imager project for the VLTI. Its main goal is to characterize young extra-solar planetary systems and exozodiacal dust around southern main-sequence stars. In this paper, we present an update of the project and key technology pathways to improve the contrast achieved by the VLTI. In particular, we discuss the possibility to use integrated optics, proven in the near-infrared, in the thermal near-infrared (L and M bands, 3-5~$\mu$m) and advanced fringe tracking strategies. We also address the strong exoplanet science case (young exoplanets, planet formation, and exozodiacal disks) offered by this wavelength regime as well as other possible science cases such as stellar physics (fundamental parameters and multiplicity) and extragalactic astrophysics (active galactic nuclei and fundamental constants). Synergies and scientific preparation for other potential future instruments such as the Planet Formation Imager are also briefly discussed.