# A Pathfinder for Imaging Extrasolar Earths from the Ground

## TL;DR

The paper discusses the SCExAO system on the Subaru telescope, which advances ground-based high-contrast imaging of extrasolar planets, enabling detailed characterization and potential future detection of Earth-like planets.

## Contribution

Introduction of the SCExAO system with novel wavefront sensing and coronagraphy, demonstrating high-contrast imaging capabilities and initial characterization of exoplanet candidates.

## Key findings

- Clarified properties of candidate companions around $$ And, LkCa 15, and HD 163296.
- Identified $$ And as a likely low-gravity, planet-mass object.
- Revealed that some signals previously thought to be planets are actually disk features.

## Abstract

The Subaru Coronagraphic Extreme Adaptive Optics (SCExAO) project is an instrument on the Subaru telescope that is pushing the frontiers of what is possible with ground-based high-contrast imaging of extrasolar planets. The system features key breakthroughs in wavefront sensing and coronagraphy to yield extremely high Strehl ratio corrections and deep planet-to-star contrasts, even for optically faint stars. SCExAO is coupled to a near-infrared integral field spectrograph -- CHARIS -- yielding robust planet spectral characterization. In its first full year of operations, SCExAO has already clarified the properties of candidate companions around $\kappa$ And, LkCa 15, and HD 163296, showing the former to be a likely low-gravity, planet-mass object and the latter two to be misidentified disk signals. SCExAO's planet imaging capabilities in the near future will be further upgraded; the system is emerging as a prototype of the kind of dedicated planet-imaging system that could directly detect an Earth-like planet around a nearby low-mass star with Extremely Large Telescopes like the Thirty Meter Telescope.