Imaging Discovery of Other Worlds Around Nearby Stars

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Over the past 20 years, the number of known exoplanets has grown exponentially to close to 1,000. The vast majority of these exoplanets orbit very close to their primary star (the so called hot Jupiters), but a few of them are low mass Earth-size planets in orbit around lower mass stars, possibly in the systems' habitable zones where liquid water, and life-as-we-know-it, could exist. While those discoveries are very exciting, what we know about these exoplanets is still very limited, as the vast majority of them have been discovered using indirect techniques. Detailed photometry and spectroscopy are needed to properly characterize planets, but this detailed analysis has only been conducted on a few to date due to limitations of existing instrumentation. **The direct exoplanet imaging technique remains the simplest way to characterize an exoplanet. When the light of a planet is directly detected, a spectrograph can be used to: study the planet atmospheric composition; estimate its atmospheric temperature/luminosity; evaluate its surface gravity; study the effect of clouds and, for rocky planets; find signs of life. Direct exoplanet imaging is a challenging endeavor due to the small star/planet angular separation and large luminosity ratio between the host star and the planet, from 100,000 times fainter for a warm young Jupiter-like planet to tens of billion of times fainter for an Earth-like planet. **After 10 years of development, a first wave of dedicated, facility-class, highly-optimized exoplanet imaging instruments is being shipped to observatories. My team (also the building team of the Gemini Planet Imager, GPI) has secured 900h of observing time on GPI for a nearby 600 stars campaign to find and characterize approximately 50 new warm Jupiter-like planets (10 times more than currently imaged). GPI will achieve 100x deeper contrast than existing instruments by the use of a starlight blocking mask and precise wavefront control, allowing a unique view of young and nearby planetary systems.**This NSERC Discovery grant will enable me to fund two graduate students that will join the GPI team for this exciting adventure. The students may acquire, reduce and analyze GPI data, help organize the campaign and/or perform detailed analyses, such as orbit fitting, stability studies for multi-planet systems and search for photometric/spectroscopic time variations generated by changing cloud cover. Part of their time will be allocated to further develop the image subtraction algorithms and study possible upgrades to the instrument. **The students will also participate in the design process of their future exoplanet imaging tools, by performing numerical simulations for the planned Thirty Meter Telescope (TMT) and a space exoplanet imaging telescope (MAPLE). The TMT is part of the next generation of extremely large telescopes currently in the designing/building stage, representing a 3x increase in aperture to current facilities. The TMT will achieve unparalleled resolution, allowing to directly image Jovian planets at solar system scale (< 10 astronomical units (AU), i.e. 10x the Earth-Sun separation). With optimized instruments that the students will help conceive, it may even be possible to directly image Earth-like planets around the nearest low mass stars. The project MAPLE is a new Canadian-led space telescope concept that I am leading. The students will analyze the performance of this 50 cm diameter visible-band space telescope to directly image, around the nearest stars, the reflected light of super-Earth/ice giant planets in orbit around the nearest stars. **The expertise gained by studying those concepts will be applicable to future observatories that will one day take a picture of an Earth-like planet.