A method to directly image exoplanets in multi-star systems such as Alpha-Centauri

TL;DR

This paper introduces a novel technique for directly imaging exoplanets in multi-star systems like Alpha Centauri by correcting light from multiple stars simultaneously, even when one star is outside the deformable mirror's control region.

Contribution

The method enables direct imaging of planets in binary systems by correcting aberrations from both stars simultaneously, leveraging aliasing effects to handle stars outside the DM's control region.

Findings

Successfully corrects light from both stars in simulations

Enables imaging of planets in binary systems beyond current DM limits

Uses aliasing effects to extend control region for exoplanet imaging

Abstract

Direct imaging of extra-solar planets is now a reality, especially with the deployment and commissioning of the first generation of specialized ground-based instruments such as the Gemini Planet Imager and SPHERE. These systems will allow detection of Jupiter-like planets $10^7$ times fainter than their host star. Obtaining this contrast level and beyond requires the combination of a coronagraph to suppress light coming from the host star and a wavefront control system including a deformable mirror (DM) to remove residual starlight (speckles) created by the imperfections of telescope. However, all these current and future systems focus on detecting faint planets around single host stars, while several targets or planet candidates are located around nearby binary stars such as our neighboring star Alpha Centauri. Here, we present a method to simultaneously correct aberrations and diffraction of light coming from the target star as well as its companion star in order to reveal planets orbiting the target star. This method works even if the companion star is outside the control region of the DM (beyond its half-Nyquist frequency), by taking advantage of aliasing effects.