S. Mark Ammons (Lawrence Livermore National Laboratory), Gemini Planet Imager team (GPI)
Keywords: adaptive optics, contrast, planet, coronagraph, woofer, tweeter
Abstract:
A long-standing challenge has been to directly image faint extrasolar planets adjacent to their host suns, which may be ~1-10 million times brighter than the planet. The Gemini Planet Imager is the worlds most advanced high-contrast adaptive optics system for detecting and characterizing planets outside of our solar system. An order of magnitude more sensitive than any existing facility, GPI will detect a previously unstudied population of young analogs to the giant planets of our solar system and help determine how planetary systems form. GPI employs a 44×44 woofer-tweeter adaptive optics system with a Shack-Hartmann wavefront sensor operating at 1 kHz. The controller uses Fourier-based reconstruction and modal gains optimized from system telemetry. GPI has an apodized Lyot coronagraph to suppress diffraction and a near-infrared integral field spectrograph for obtaining planetary spectra. After several first-light commissioning runs on the Gemini telescope, GPI has obtained 10^6 contrast at a separation of 0.75, the highest imaging contrast ratio yet demonstrated from the ground for this separation. I will present first light results with the GPI, show estimations of system contrast for short exposure times, and discuss current performance limitations.
Date of Conference: September 9-12, 2014
Track: Adaptive Optics & Imaging