Research

・High-contrast imaging explorations for exoplanets and protoplanetary disks

I have been working on directly imaging new young exoplanets using Subaru and Keck telescopes. Basically our targets are at the very young stage where planets are luminous enough to be detected at near-infrared wavelengths. We utilize the adaptive optics technique that corrects wavefront distortions by Earth’s atmospheric turbulence and high-contrast post-processing techniques (differential imaging) so that we can remove bright starlight and explore faint signatures of planets at small angular separations around the central star.

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Directly-imaged companions of Kap And b (Uyama et al. 2020a), and HIP 79462B (Uyama et al. 2017a). North is up and east is left, the central star is masked by the algorithm.

This technique also helps to reveal a variety of substructures in protoplanetary disks where planets are being formed, part of which is expected to be signatures of planet-disk interactions. Thus detecting planets embedded in disks will provide the most useful information about planet formation mechanisms and planet-disk interactions. We have explored young stellar objects (<10 Myr) and detected a lot of disk features as shown below, but the detection ratio of planets in the disks is quite low compared with that of the disk features for the time being.

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Our high-contrast imaging of asymmetric features in disks of SR 21 (upper left: Uyama et al. 2020e), LkHα 330 (upper middle: Uyama et al. 2018), HD 34700 (upper right: Uyama et al. 2020c), CQ Tau (lower left: Uyama et al. 2020b), and J0337 (lower right: Uyama et al. 2022a). Particularly we discovered the spiral feature in the CQ Tau disk and the large cavity in the J0337 disk.

・High-contrast imaging characterizations of directly-imaged planets

・Exploring hydrogen emissions around young stellar objects – accreting protoplanets and jets

this section is still under construction