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High-contrast imaging of exoplanets and protoplanetary disks depends on wavefront sensing and correction made by adaptive optics instruments. Classically, wavefront sensing has been conducted at optical wavelengths, which made high-contrast imaging of red targets such as M-type stars or extincted T Tauri stars challenging. Keck/NIRC2 has combined near-infrared (NIR) detector technology with the pyramid wavefront sensor (PWFS). With this new module we observed SR~21, a young star that is brighter at NIR wavelengths than at optical wavelengths. Compared with the archival data of SR~21 taken with the optical wavefront sensing we achieved $sim$20% better Strehl ratio in similar natural seeing conditions. Further post-processing utilizing angular differential imaging and reference-star differential imaging confirmed the spiral feature reported by the VLT/SPHERE polarimetric observation, which is the first detection of the SR~21 spiral in total intensity at $L^prime$ band. We also compared the contrast limit of our result ($10^{-4}$ at $0farcs4$ and $2times10^{-5}$ at $1farcs0$) with the archival data that were taken with optical wavefront sensing and confirmed the improvement, particularly at $leq0farcs5$. Our observation demonstrates that the NIR PWFS improves AO performance and will provide more opportunities for red targets in the future.
We present observations of the nearby (D$sim$100,pc) Herbig star HD~163296 taken with the vortex coronograph at Keck/NIRC2 in the L band (3.7~$mu$m), to search for planetary mass companions in the ringed disc surrounding this pre-main sequence star.
We present $L$-band imaging of the PDS 70 planetary system with Keck/NIRC2 using the new infrared pyramid wavefront sensor. We detected both PDS 70 b and c in our images, as well as the front rim of the circumstellar disk. After subtracting off a mod
Hydrodynamical simulations of planet-disk interactions suggest that planets may be responsible for a number of the sub-structures frequently observed in disks in both scattered light and dust thermal emission. Despite the ubiquity of these features,
We search for signs of ongoing planet-disk interaction and study the distribution of small grains at the surface of the transition disk around RXJ1615.3-3255 (RX J1615). We observed RXJ1615 with VLT/SPHERE. We image the disk for the first time in sca
We present Subaru/SCExAO+CHARIS broadband ($JHK$-band) integral field spectroscopy of HD 34700 A. CHARIS data recover HD 34700 As disk ring and confirm multiple spirals discovered in Monnier et al. (2019). We set limits on substellar companions of $s