Abstract: In the last thirty years, over 3000 planets have been discovered orbiting nearby stars. This flood of new worlds includes planets unlike any found in our own Solar System, from Jupiter-mass planets with years as short as our day to exotic rocky worlds twice as massive as the Earth. While our understanding of exoplanets' diversity has leapt forward in recent years, fundamental questions remain. For example, what are the dominant planet formation pathways? How do planets acquire their atmospheres? Is there life on other worlds? These questions can only be answered through observations of exoplanets’ spectra, where the characteristic imprints of atoms and molecules making up a planet’s atmosphere are revealed. The most promising method for obtaining spectra of diverse exoplanets is direct imaging: by nulling the light of the parent star with an optical device called a coronagraph, the planet itself can be seen and its light dispersed into a spectrum. So far, only extremely young, massive worlds have been directly imaged, while older, lower mass objects like the Earth remain hidden in the glare of their host stars. In this talk, I will describe two avenues for advancing the state-of-the-art in exoplanet imaging: 1) detecting low-mass exoplanets at Solar System separations with the W. M. Keck Observatory and Thirty Meter Telescope via predictive wavefront control and focal plane wavefront sensing, and 2) characterizing the atmospheres of directly imaged planets with polarimetry -- an untapped method for probing the physics of clouds in the atmospheres of other worlds.
About the speaker: Rebecca Jensen-Clem Kirkland, Washington before studying physics at MIT and astrophysics at Caltech. Since 2020, she has been an astronomy professor at the University of California Santa Cruz. Her research focuses on the technologies that help us directly image other planets in our galaxy. In particular, she invents new ways to counteract the blurring effects of Earth's atmospheric turbulence using a technique called adaptive optics. She also studies the atmospheres of gas giant planets in other solar systems by observing their polarized light.
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