Imaging faint companions within one diffraction beam width of stars
with a vortex coronagraph

Gene Serabyn (JPL)

A vortex coronagraph operating on our extreme adaptive optics
"well-corrected subaperture" at Palomar has recently allowed us to
image the three HR8799 planets with our 1.5 m aperture, and, in
another system, to image a low-mass stellar companion only one
diffraction beamwidth from its primary. This talk describes the
operation of the vortex coronagraph, the wavefront improvements that
have allowed us to reach small-angle contrasts of ~ 10-5, and our
recent observational results. These first results with the vortex
coronagraph hold great promise both for future ground-based and
space-based telescopes. In the former case, a well-corrected
subaperture is a promising way to reach very high contrasts with first
generation instrumentation, while in the latter case, much smaller
space-based telescopes can be considered for exoplanet detection and
characterization.