EXPERIMENTAL DESIGN FOR THE GEMINI PLANET IMAGER

The Gemini Planet Imager (GPI) is a high-performance adaptive optics system being designed and built for the Gemini Observatory. GPI is optimized for high-contrast imaging, combining precise and accurate wavefront control, diffraction suppression, and a speckle-suppressing science camera with integral field and polarimetry capabilities. The primary science goal for GPI is the direct detection and characterization of young, Jovian-mass exoplanets. For plausible assumptions about the distribution of gas giant properties at large semimajor axes, GPI will be capable of detecting more than 10% of gas giants more massive than 0.5 MJ around stars younger than 100 Myr and nearer than 75 pc. For systems younger than 1 Gyr, gas giants more massive than 8 MJ and with semimajor axes greater than 15 AU are detected with completeness greater than 50%. A survey targeting young stars in the solar neighborhood will help determine the formation mechanism of gas giant planets by studying them at ages where planet brightness depends upon formation mechanism. Such a survey will also be sensitive to planets at semimajor axes, comparable with the gas giants in our own solar system. In the simple, and idealized, situation in which planets formed by either the "hot-start" model of Burrows et al. or the core accretion model of Marley et al., a few tens of detected planets are sufficient to distinguish how planets form.