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arXiv · 2204.10002

The coherent differential imaging on speckle area nulling (CDI-SAN) method for high-contrast imaging under speckle variation

Jun Nishikawa
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Abstract

Differential imaging is a postprocessing method to obtain high contrast, often used for exoplanet searches. The coherent differential imaging on speckle area nulling (CDI-SAN) method was developed to detect a faint exoplanet lying beneath residual speckles of a host star. It utilizes image acquisitions faster than the stellar speckle variation synchronized with five shapes of a deformable mirror repeatedly. By using the only the integrated values of each of the five images and square differences for a long interval of observations, the light of the exoplanet could be separated from the stellar light. The achievable contrast would reach to almost the photon-noise limit of the residual speckle intensities under appropriate conditions. The CDI-SAN can be applied to both ground-based and space telescopes.

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Jun Nishikawa. 2022-04-21. The coherent differential imaging on speckle area nulling (CDI-SAN) method for high-contrast imaging under speckle variation. https://doi.org/10.3847/1538-4357%2Fac5f44

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