Department of Astronomy 2022-2023 Colloquium Series Presents:

Exoplanets at High Spatial and Spectral Resolution

Abstract: Although thousands of exoplanets have been discovered, only a small fraction have been studied in detail. By spatially resolving planets from their host stars, we can directly characterize them as individual worlds. I will discuss two novel techniques to study directly imaged exoplanets in unprecedented detail: high-dispersion coronagraphy and long-baseline interferometry. With high-dispersion coronagraphy, we can study exoplanet atmospheres in extreme spectral detail. By spectrally resolving molecular absorption features in planetary atmospheres, we can measure elemental abundances, planetary radial velocities, and planetary spins. Long-baseline interferometry with VLTI gives us the spatial resolution of a 140-meter telescope, enabling the positions of exoplanets to be measured to within 50 microarcseconds, the circumplanetary environment to be resolved to sub-au scales, and the first direct detection of a radial-velocity discovered exoplanet. Both of these techniques offer improved sensitivity over classical coronagraphy at the diffraction limit and have opened the window to study the composition of typical giant planets at 1-10 au like our own Jupiter. I will present recent science results with both techniques and discuss their future prospects, such as the spectroscopy of terrestrial planets on the next generation of extremely large telescopes.

https://jasonwang.space/#home