Direct imaging surveys that select targets using proper motion accelerations (PMA) measured by the Hipparcos and Gaia astrometry has recently been producing some interesting discoveries of substellar companions. Those discoveries demonstrate the measurements of PMAs are available to pick up nearby stars that are likely hosting co-moving companions and more efficiently identify substellar companions than conventional blind surveys. We will conduct the high-contrast imaging of targets selected with the PMA catalog using SCExAO/CHARIS of the Subaru Telescope, providing the sensitivity deep enough to discover giant planets with masses down to 4 Jupiter masses. We select 5 Sun-like stars with the ages of 60–500 Myr, which are inferred by applying the gyrochronology technique to their rotation periods measured by the TESS telescope. The PMA measurements are combined with the high-contrast imaging data and/or the radial velocities measurements of the targets to constrain the orbit of a detected companion and dynamically infer its mass. We also characterize the companion’s near-infrared spectrum taken with the CARHIS spectroscopy. As a result, our approach leads to the important test of the atmosphere/evolutionary models of planets.
This document was translated from LATEX by HEVEA.