A dual-mask coronagraph for observing faint companions to binary stars

TL;DR

This paper introduces a dual-mask coronagraph technique designed to enhance the observation of faint companions near binary stars by suppressing the bright stellar light more effectively than traditional methods.

Contribution

It proposes a novel dual-mask coronagraph system with active control for observing faint companions to binary stars, improving upon existing coronagraphic techniques.

Findings

Dual-mask coronagraph effectively suppresses light from both stars.

Performance surpasses band-limited and single-mask Lyot coronagraphs.

Method enables detection of faint companions near binary stars.

Abstract

Observations of binary stars for faint companions with conventional coronagraphic methods are challenging, as both targets will be bright enough to obscure any nearby faint companions if their scattered light is not suppressed. We propose coronagraphic examination of binary stars using an apodized pupil Lyot coronagraph and a pair of actively-controlled image plane masks to suppress both stars simultaneously. The performance is compared to imaging with a band-limited mask, a dual-mask Lyot coronagraph and with no coronagraph at all. An imaging procedure and control system for the masks are also described.