Millisecond exoplanet imaging: I. method and simulation results

One of the top priorities in observational astronomy is direct imaging and characterization extrasolar planets (exoplanets) planetary systems. Direct images rocky exoplanets are particular interest search for life beyond Earth, but they tend to be rather challenging targets since orders-of-magnitude dimmer than their host stars separated by small angular distances that comparable classical λ / D diffraction limit, even coming generation 30 m class telescopes. Current planned efforts ground-based combine high-order adaptive optics (AO) with a stellar coronagraph observing at wavelengths ranging from visible mid-IR. The primary barrier achieving high contrast current methods quasi-static speckles, caused largely non-common path aberrations (NCPAs) optical train. Recent work has demonstrated millisecond imaging, which effectively “freezes” atmosphere’s turbulent phase screens, should allow wavefront sensor (WFS) telemetry used as probe system measure NCPAs. Starting realistic model telescope an AO coronagraph, this paper provides simulations several closely related regression models take advantage WFS coronagraph’s science camera. simplest model, called naïve estimator, does not treat noise other sources information loss WFS. Despite its flaws, one presented herein, estimator useful estimate NCPA ∼ 0.5 radian RMS ( ≈<!-- ≈ <mml:mn>13 ), accuracy 0.06 1 min simulated sky time on magnitude 8 star. bias-corrected generalizes account A simulation 4 included 0.05 130 ) extended exoplanet scene. joint simultaneously achieved 5 ×<!-- × <mml:msup> 10 −<!-- − <mml:mn>3 scene was free self-subtraction artifacts typically associated differential imaging. σ<!-- σ <mml:mn>1.7 4 distance star 2.1 . These values very best on-sky results obtained multi-wavelength observations employ both (ADI) spectral (SDI). This performance despite fact our quasi-monochromatic, makes SDI impossible, nor do have diurnal field rotation, ADI impossible. error covariance matrix shows substantial correlations estimation errors, indicating intensity need estimated self-consistently achieve contrast.