The Subaru Coronagraphic Extreme Adaptive Optics (SCExAO) instrument is a multipurpose highcontrast imaging platform designed for the discovery and detailed characterization of exoplanetary systems and serves as a testbed for high-contrast imaging technologies for ELTs. It is a multi-band instrument which makes use of light from 600 to 2500 nm allowing for coronagraphic direct exoplanet imaging of the inner 3 λ/D from the stellar host. Wavefront sensing and control are key to the operation of SCExAO. A partial correction of low-order modes is provided by Subaru's facility adaptive optics system with the final correction, including high-order modes, implemented downstream by a combination of a visible pyramid wavefront sensor and a 2000-element deformable mirror. The well corrected NIR (y-K bands) wavefronts can then be injected into any of the available coronagraphs, including but not limited to the phase induced amplitude apodization and the vector vortex coronagraphs, both of which offer an inner working angle as low as 1 λ/D. Non-common path, loworder aberrations are sensed with a coronagraphic low-order wavefront sensor in the infrared (IR). Low noise, high frame rate, NIR detectors allow for active speckle nulling and coherent differential imaging, while the HAWAII 2RG detector in the HiCIAO imager and/or the CHARIS integral field spectrograph (from mid 2016) can take deeper exposures and/or perform angular, spectral and polarimetric differential imaging. Science in the visible is provided by two interferometric modules: VAMPIRES and FIRST, which enable sub-diffraction limited imaging in the visible region with polarimetric and spectroscopic capabilities respectively. We describe the instrument in detail and present preliminary results both on-sky and in the laboratory.

Direct imaging of protoplanetary disks promises to provide key insight into the complex sequence of processes by which planets are formed. However imaging the innermost region of such disks (a zone critical to planet formation) is challenging for traditional observational techniques (such as near-IR imaging and coronagraphy) due to the relatively long wavelengths involved and the area occulted by the coronagraphic mask. Here we introduce a new instrument -VAMPIRES -which combines nonredundant aperture-masking interferometry with differential polarimetry to directly image this previously inaccessible innermost region. By using the polarisation of light scattered by dust in the disk to provide precise differential calibration of interferometric visibilities and closure phases, VAMPIRES allows direct imaging at and beyond the telescope diffraction limit. Integrated into the SCExAO system at the Subaru telescope, VAMPIRES operates at visible wavelengths (where polarisation is high) while allowing simultaneous infrared observations conducted by HICIAO. Here we describe the instrumental design and unique observing technique and present the results of the first on-sky commissioning observations, validating the excellent visibility and closure phase precision which are then used to project expected science performance metrics.

For one decade, the spectral-type and age of the ρ Oph object IRS-48 were subject to debates and mysteries. Modelling its disk with mid-infrared to millimeter observations led to various explanations to account for the complex intricacy of dust-holes and gas-depleted regions. We present multi-epoch highangular-resolution interferometric near-infrared data of spatially-resolved emissions in its first 15AU, known to have very strong Polycyclic Aromatic Hydrocarbon (PAH) emissions within this dust-depleted region. We make use of new Sparse-Aperture-Masking data to instruct a revised radiative-transfer model where SED fluxes and interferometry are jointly fitted. Neutral and ionized PAH, Very Small Grains (VSG) and classical silicates are incorporated into the model; new stellar parameters and extinction laws are explored. A bright (42L ) central-star with A v =12.5mag and R v =6.5 requires less near-infrared excess: the inner-most disk at ≈1AU is incompatible with the data. The revised stellar parameters place this system on a 4 Myr evolutionary track, 4 times younger than previous estimations, in better agreement with the surrounding ρ Oph region and disk-lifetimes observations. The disk-structure converges to a classical-grains outer-disk from 55AU combined with a fully resolved VSG&PAH-ring, at 11-26 AU. We find two over-luminosities in the PAH-ring at color-temperatures consistent with the radiative transfer simulations; one follows a Keplerian circular orbit at 14AU. We show a depletion of a factor ≈5 of classical dust grains compared to VSG&PAH: the IRS-48 disk is nearly void of dust-grains in the first 55 AU. A 3.5M Jup planet on a 40AU orbit qualitatively explains the new disk-structure.Subject headings: protoplanetary disks -infrared: planetary systems -radiative transfer -stars: pre-main sequence -stars: individual: IRS-48