Whack-a-speckle: focal plane wavefront sensing in theory and practice with a deformable secondary mirror and 5-micron camera

Long exposures from adaptive optic systems show a diffraction limited core superimposed on a halo of uncorrected light from a science target, and the addition of various long-lived speckles that arise from uncorrected aberrations in the telescope system. The presence of these speckles limit the detection of extra-solar planets at a few diffraction widths from the primary source. Focal plane wavefront sensing uses the deformable secondary mirror of the MMT adaptive optics system to systematically remove the presence of long-lived speckles in a high-contrast image, and also test for the incoherent source that represents a separate astronomical target nearby. We use the Clio 5 micron camera (with its coronagraphic capabilities) to modulate long lived speckles and present initial on-sky results of this technique.