Search

HiCIAO (the High‐Contrast Instrument with Adaptive Optics) is a high‐contrast instrument for the 8.2‐meter Subaru Telescope. The instrument is a near‐infrared camera which benefits from a new adaptive optics (AO) system on the Subaru Telescope (AO188). The instrument realizes the high contrast with a help of AO188, a classical Lyot coronagraph, and three differential imaging techniques (polarimetric, spectral, and angular). Besides the differential imaging modes, HiCIAO also offers a normal imaging mode which covers 20″×20″ FOV with 0.″01 pixel−1 resolution, and a pupil viewing mode for a precise alignment of the Lyot stop on the pupil image. The expected contrasts are 105.5 at 1.″0 separation and 104 at 0.″1 separation from a central star in the spectral differential imaging mode. The instrument is currently in its commissioning phase after the first‐light observation in December 2008. This paper is an introductory review of the instrument.

The Subaru High‐contrast Coronagraphic Imager for Adaptive Optics (HiCIAO) instrument is participating in the planet hunt with its direct imaging survey, the Subaru Strategic Exploration of Exoplanets and Disks (SEEDS), from which binary stars are excluded. However, these systems are expected to harbor a population of planets comparable in number to that of single stars, but differing in many aspects, such as the distribution of planet mass, orbital separation, and eccentricity. Measuring these deviations would unlock a wealth of information on the processes by which planets form and evolve, providing much‐needed constraints to theory. The logical next step is therefore to complement SEEDS with a sister project focusing on binary stars: SPOTS, a “Search for Planets Of Two Stars.” We propose a direct imaging survey for circumbinary planets of very tight binaries and circumstellar planets of wide binaries.