The Gemini Planet Imager is the next generation adaptive optics instrument being built for the Gemini Telescope. The goal is to image extrasolar planets orbiting nearby stars. See the GPI Overview PDF (hires, lowres).

WHO: GPI is being built by a consortium of U.S. and Canadian institutions, funded by the Gemini Observatory, which is an international partnership comprising the U.S.A., U.K., Canada, Australia, Argentina, Brazil & Chile.

WHEN: First light and science operations are planned for early 2011. GPI successfully held its preliminary design review (PDR) in May 2007 and critical design review (CDR) in May 2008. A delta CDR was successful in March, 2009. GPI is currently in a phase of procurement and fabrication, with testing and integration through the end of 2009. Readiness review will be held in the Fall, 2010, followed by delivery at the end of 2010.

WHERE: Initial deployment at Gemini South, a telescope with an 8-meter diameter mirror located on Cerro Pachon (Chilean Andes) at an altitude of 2715 meters (9000 feet). Later, GPI may also be used at the twin facility Gemini North, which is located on Mauna Kea, Hawaii.

WHY: We want to directly detect the light from an extrasolar planet to determine its mass and composition, with an ultimate goal of determining the nature of our own planetary system. More than 200 extrasolar planets are now known, but mostly through indirect Doppler techniques that indicate the planet's mass and orbit. If we can directly pick out a planet from the star's glare, we can use spectroscopy to measure the planet's size, temperature, gravity, and even the composition of its atmosphere. By targeting many stars we will understand how common or unusual our own planetary system may be.

HOW: We will create advanced adaptive optics using silicon microchip deformable mirrors to remove atmospheric turbulence, and coronagraphic masks to block the diffracted light from the parent star.

WHAT: GPI will provide diffraction limited images between 0.9 and 2.4 microns. Bright natural guide stars (I<9 mag) are required for optimal performance of the GPI adaptive optics system. The system will be able to see objects ten million times fainter than their parent star at separations of 0.2-1 arcsecond in a 1-2 hour exposure. The science instrument will provide spectroscopy of any object observed. This allows us to detect warm planets (up to a billion years in age) through their infrared light. We can also measure the polarization of light to see faint disks of dust from other solar systems' comet and asteroid belts.

SO WHAT:GPI will produce the first comprehensive survey of giant planets in the region where giant planets exist in our solar system - from 5 to 40 astronomical units radius. Dozens of these planets will be bright enough for high signal-to-noise ratio spectroscopy, moving our studies of extrasolar planets into the realm of detailed astrophysics.