Special Physics Seminar

Directly Imaging Exoplanetary Systems:
What have we learned and where are we going?

Maxwell Millar-Blanchaer

Jet Propulsion Laboratory

In the past twenty years we have discovered over 3000 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. With the exception of direct imaging, all of these techniques rely on indirect methods of planet detection. Indirect methods have proven to be extremely useful in carrying out statistical studies of exoplanet populations, however, with a few exceptions, detailed characterization of planetary systems discovered with these methods remains out of reach. Though currently limited to young Jupiter-mass planets, direct imaging has enabled the direct measurement 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 orbital 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 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, including results from its polarimetry mode which I have worked on extensively. I will then review some of the new techniques being planned and brought online within the next few years by myself and others, that will probe exoplanet atmospheres in new ways and detect even fainter planets. Finally, I will discuss the long-term direction of the field and scientific advances, such as the detection of nearby earth-like planets in reflected light, that will be made possible with second generation instruments that are starting to be developed for the Thirty Meter Telescope.