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 a Cold Jovian Exoplanet in Orbit around the Sun-like Star GJ 504Kuzuhara, M.; et al., [Unknown]; Thalmann, C.D. General rightsIt is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s) and/or copyright holder(s), other than for strictly personal, individual use, unless the work is under an open content license (like Creative Commons). Disclaimer/Complaints regulationsIf you believe that digital publication of certain material infringes any of your rights or (privacy) interests, please let the Library know, stating your reasons. In case of a legitimate complaint, the Library will make the material inaccessible and/or remove it from the website. Please Ask the Library: http://uba.uva.nl/en/contact, or a letter to: Library of the University of Amsterdam, Secretariat, Singel 425, 1012 WP Amsterdam, The Netherlands. You will be contacted as soon as possible. Download date: 13 May 2018The Astrophysical Journal, 774:11 (18pp) ABSTRACT Several exoplanets have recently been imaged at wide separations of >10 AU from their parent stars. These span a limited range of ages (<50 Myr) and atmospheric properties, with temperatures of 800-1800 K and very red colors (J − H > 0.5 mag), implying thick cloud covers. Furthermore, substantial model uncertainties exist at these young ages due to the unknown initial conditions at formation, which can lead to an order of magnitude of uncertainty in the modeled planet mass. Here, we report the direct-imaging discovery of a Jovian exoplanet around the Sun-like star GJ 504, detected as part of the SEEDS survey. The system is older than all other known directly imaged planets; as a result, its estimated mass remains in the planetary regime independent of uncertainties related to choices of initial conditions in the exoplanet modeling. Using the most common exoplanet cooling model, and given the system age of 160 +350 −60 Myr, GJ 504b has an estimated mass of 4 +4.5 −1.0 Jupiter masses, among the lowest of directly imaged planets. Its projected separation of 43.5 AU exceeds the typical outer boundary of ∼30 AU predicted for the core accretion mechanism. GJ 504b is also significantly cooler (510 +30 −20 K) and has a bluer color (J − H = −0.23 mag) than previously imaged exoplanets, suggesting a largely cloud-free atmosphere accessible to spectroscopic characterization. Thus, it has the potential of providing novel insights into the origins of giant planets as well as their atmospheric properties.

We present SCExAO/CHARIS high-contrast imaging/JHK integral field spectroscopy of κ And b, a directly-imaged low-mass companion orbiting a nearby B9V star. We detect κ And b at a high signal-to-noise and extract high precision spectrophotometry using a new forward-modeling algorithm for (A-)LOCI complementary to KLIP-FM developed by Corresponding author: Thayne Currie thayne.m.currie@nasa.gov,currie@naoj.org Currie et al. Pueyo et al. (2016). κ And b's spectrum best resembles that of a low-gravity L0-L1 dwarf (L0-L1γ). Its spectrum and luminosity are very well matched by 2MASSJ0141-4633 and several other 12.5-15 M J free floating members of the 40 M yr-old Tuc-Hor Association, consistent with a system age derived from recent interferometric results for the primary, a companion mass at/near the deuterium-burning limit (13 +12 −2 M J ), and a companion-to-primary mass ratio characteristic of other directly-imaged planets (q ∼ 0.005 +0.005 −0.001 ). We did not unambiguously identify additional, more closely-orbiting companions brighter and more massive than κ And b down to ρ ∼ 0. ′′ 3 (15 au). SCExAO/CHARIS and complementary Keck/NIRC2 astrometric points reveal clockwise orbital motion. Modeling points towards a likely eccentric orbit: a subset of acceptable orbits include those that are aligned with the star's rotation axis. However, κ And b's semimajor axis is plausibly larger than 75 au and in a region where disk instability could form massive companions.Deeper κ And high-contrast imaging and low-resolution spectroscopy from extreme AO systems like SCExAO/CHARIS and higher resolution spectroscopy from Keck/OSIRIS or, later, IRIS on the Thirty Meter Telescope could help clarify κ And b's chemistry and whether its spectrum provides an insight into its formation environment.

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