Directly Imaging Exoplanetary Systems in Polarized Light

In the past twenty years we have discovered nearly 4000 extrasolar planets, allowing us to begin to answer fundamental questions about our place in the universe. These discoveries have largely been fueled by the development and refinement of planet detection techniques such as the transit, radial-velocity, microlensing and direct imaging methods. Though currently limited to young Jupiter-mass planets, direct imaging has enabled the direct characterization of exoplanet atmospheres through multi-wavelength and spectroscopic measurements using light emitted by the planets themselves. In addition, direct imaging can provide critical information about the architecture of these systems through long-term orbital monitoring and the imaging of neighbouring debris disks—extrasolar analogs to our own asteroid and Kuiper belts. In this context high-contrast imaging polarimetry has emerged as a transformative tool to detect and characterize circumstellar disks. In this talk I will provide an overview of the current state of the direct imaging field, with a focus on recent results from the Gemini Planet Imager. I will then review some of the new techniques being planned and brought online within the next few years that will probe exoplanet atmospheres in new ways and detect even fainter planets. In particular, polarimetric methods current being used to characterize brown dwarfs cloud properties will be applied to directly imaged exoplanets to constrain cloud dynamics and particle properties. Finally, I will discuss the long-term direction of the field and scientific advances, such as the ability to detect nearby earth-like planets in reflected polarized light, that will be made possible by the Planetary Systems Imager, a second generation instrument being developed for the Thirty Meter Telescope.


Maxwell A. Millar-Blanchaer (Jet Propulsion Laboratory)

January 28, 2019
11:00am - 12:00pm