Searching for Accreting Protoplanets with SCExAO/CHARIS Kernel Phase Interferometry

Alexander Chaushev

Discovering new actively-accreting protoplanets is crucial to answering open questions about planet formation. However, identifying such planets on true Solar System scales is technically challenging. The large distances to star-forming regions require moderate contrast at high angular resolutions which is difficult to achieve even with today's largest telescopes and extreme adaptive optics (AO) systems. Novel approaches are needed to process AO-corrected data in order to reach these planets.
Kernel phase interferometry (KPI) is a data processing technique that allows for the detection of asymmetries arising from companions or disks in high-Strehl AO-corrected images, close to or beyond the classical diffraction limit of the telescope. KPI allows us to access a region of parameter space interior to current direct imaging studies using coronagraphy, where planet formation is thought to be more efficient.
Here we present results from a program which validates the use of KPI with the SCExAO/CHARIS instrument on the Subaru telescope. As well as demonstrating KPI and characterising SCExAO/CHARIS for future observations with the technique, we present a search for signs of Br-gamma accretion around multiple young stars with candidate protoplanets. Finally we also show a search, in K-band continuum, for signs of currently known candidates and for new companions interior to those of previous studies.