Prospects for exoplanet imaging in multi-star systems with starshades

TL;DR

This paper investigates starshade-based methods for directly imaging exoplanets in multi-star systems, focusing on hybrid techniques combining starshades with coronagraphs and wavefront control to suppress off-axis starlight.

Contribution

It introduces novel hybrid approaches for starshade missions, including combining starshades with coronagraphs and wavefront control to improve imaging of multi-star systems.

Findings

Hybrid starshade and coronagraph techniques can effectively suppress off-axis starlight.

Wavefront control with SNWC enables high-contrast imaging around on-axis stars.

Simulation results demonstrate potential for WFIRST to image multi-star systems.

Abstract

We explore the capabilities of a starshade mission to directly image multi-star systems. In addition to the diffracted and scattered light for the on-axis star, a multi-star system features additional starlight leakage from the off-axis star that must also be controlled. A basic option is for additional starshades to block the off-axis stars. An interesting option takes the form of hybrid operation of a starshade in conjunction with an internal starlight suppression. Two hybrid scenarios are considered. One such scenario includes the coronagraph instrument blocking the on-axis star, with the starshade blocking off-axis starlight. Another scenario uses the wavefront control system in the coronagraph instrument and using a recent Super-Nyquist Wavefront Control (SNWC) technique can remove the off-axis stellar leakage to enable a region of high-contrast around the on-axis star blocked by the starshade.We present simulation results relevant for the WFIRST telescope.