Several mission concepts are being studied to directly image planets aroundnearby stars. It is commonly thought that directly imaging a potentiallyhabitable exoplanet around a Sun-like star requires space telescopes withapertures of at least 1m. A notable exception to this is Alpha Centauri (A andB), which is an extreme outlier among FGKM stars in terms of apparent habitablezone size: the habitable zones are ~3x wider in apparent size than around anyother FGKM star. This enables a ~30-45cm visible light space telescope equippedwith a modern high performance coronagraph or starshade to resolve thehabitable zone at high contrast and directly image any potentially habitableplanet that may exist in the system. We presents a brief analysis of theastrophysical and technical challenges involved with direct imaging of AlphaCentauri with a small telescope and describe two new technologies that addresssome of the key technical challenges. In particular, the raw contrastrequirements for such an instrument can be relaxed to 1e-8 if the missionspends 2 years collecting tens of thousands of images on the same target,enabling a factor of 500-1000 speckle suppression in post processing using anew technique called Orbital Difference Imaging (ODI). The raw light leak fromboth stars is controllable with a special wavefront control algorithm known asMulti-Star Wavefront Control (MSWC), which independently suppresses diffractionand aberrations from both stars using independent modes on the deformablemirror. We also show an example of a small coronagraphic mission concept totake advantage of this opportunity.
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