Cool Stars 14 - Submitted Abstract # 345
This version created on 05 October 2006

Gemini Planet Imager


Bruce Macintosh, LLNL
James Graham, UC Berkeley
David Palmer, LLNL
Rene Doyon, University of Montreal
Don Gavel, UC Santa Cruz
James Larkin, UCLA
Ben Oppenheimer, American Museum of Natural History
Leslie Saddlemyer, Herzberg Institute of Astrophysics
J. Kent Wallace, JPL
Brian Bauman, LLNL
Darren Erikson, Herzberg Institute of Astrophysics
Donald LLNL Phillion
Lisa Poyneer, LLNL 
Anand Sivaramakrishnan, LLNL
Remi Soummer, LLNL
Jean-Pierre Veran, HIA

The next major step on the road to space-based detection of
terrestrial planets is direct imaging of a significant population of
giant planets.  With recent advances in high-order adaptive optics,
careful system design, and advanced coronagraphy, it is possible for
an AO system on a ground-based 8-m class telescope to achieve contrast
levels of 10-7 to 10-8, sufficient to detect warm self-luminous Jovian
planets in the solar neighborhood.  Such direct detection is sensitive
to planets inaccessible to current radial-velocity surveys and allows
spectral characterization of the planets, shedding light on planet
formation and the structure of other solar systems.  We have begun the
construction of such a system for the Gemini Observatory.  Dubbed the
Gemini Planet Imager (GPI), this facility-class instrument will be
deployed in 2010  on the Gemini South telescope.  It combines a
2000-actuator MEMS-based AO system, an apodized-pupil Lyot
coronagraph, a precision infrared interferometer for real-time
wavefront calibration and control of systematic errors at the
nanometer level, and a infrared integral field spectrograph for
detection and characterization of the target planets.  GPI will be
able to achieve Strehl ratios over 0.9 at 1.65 microns and to observe
a broad sample of science targets with I band magnitudes less than 9.
I present here an overview of the GPI instrument design and an error
budget highlighting key technological challenges.  I will discuss the
similarities and differences between ground-based and space-based
coronagraphy and briefly discuss future AO capabilities on 30-m-class
extremely large telesopes.  

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