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Subaru Seminars are usually held in Room 104 of the Hilo Base Facility, adjacent to the main lobby. Everyone is welcome to attend. If you would like to give a seminar, please contact Subaru seminar organizers (Rusu Cristian Eduard, Tae-Soo Pyo, Nagayoshi Ohashi) by email : sseminar_at_subaru.naoj.org (please change"_at" to @).

January 8, Monday, 11am in 104A

" Fast Focal Plane Wavefront Sensing on Ground-Based Telescopes "

Benjamin Gerard (University of Victoria, British Columbia)


Detection and detailed characterization of sub-Jupiter mass exoplanets through extreme adaptive optics (ExAO) is a key science goal of future extremely large telescopes. This achievement, however, will be limited in sensitivity by quasi-static wavefront errors. Additional limitations arise from residual AO-corrected atmospheric wavefront error, generating ~millisecond-lifetime atmospheric speckles that will average to a smooth halo (but not to zero) over a long exposure. A solution to both of these problems is to use the science camera with a dedicated fast wavefront sensing and correction method. We develop the framework for one such method, the self-coherent camera, to be applied to ground-based telescopes. We show that with the use of a specially designed coronagraph and post-processing algorithm, recording millisecond NIR images on a photon counting camera allows a full dark hole phase and amplitude correction of both atmospheric and static speckles, without removing the incoherent planet light. Detailed simulations reach a contrast of a few times the photon noise limit after 30 seconds for a 1% bandpass on both 0th and 5th magnitude stars, illustrating that sensitivity improvement from this method could play a major role in future high contrast imaging instruments.


Seminars are also held at JAC, CFHT, and IfA.



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