The Subaru Coronagraphic Extreme-AO (SCExAO) system


The Subaru Coronagraphic Extreme Adaptive Optics (SCExAO) system, currently under development, is an instrument optimized for high contrast imaging of exoplanets and disks on the Subaru Telescope. It is unique among Extreme-AO instruments, as it is designed to be highly flexible and uses techniques recently developed for high contrast imaging from space.

Its coronagraph, based on a geometrical remapping of the beam into a edge-less apodized beam, can image planets as close as 1 lambda/D from the host star (40 mas on Subaru Telescope). In addition to these unusual optics, achieving high contrast at this small angular separation is enabled by a wavefront sensing and control architecture which is optimized for exquisite control and calibration of low order aberrations. SCExAO also includes a visible channel for high speed wavefront sensing and can also provide scientifically valuable diffraction-limited visible images.

SCExAO is therefore a pathfinder - scientifically and technically -  for future high contrast imaging instruments for the current generation of 8-10m telescopes, for future 20-30m ELTs, and also for future direct imaging space missions.

I will describe the architecture of SCExAO, and show recent results obtained on sky during our first engineering observation. I will also describe the symbiotic relationship between SCExAO development and technology development efforts for future space-based high contrast imaging.