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Title: Adaptive Optics for Direct Detection of Extrasolar Planets: The Gemini Planet Imager

Abstract

The direct detection of photons emitted or reflected by extrasolar planets, spatially resolved from their parent star, is a major frontier in the study of other solar systems. Direct detection will provide statistical information on planets in 5-50 AU orbits, inaccessible to current Doppler searches, and allow spectral characterization of radius, temperature, surface gravity, and perhaps composition. Achieving this will require new dedicated high-contrast instruments. One such system under construction is the Gemini Planet Imager (GPI.) This combines a high-order/high-speed adaptive optics system to control wavefront errors from the Earth's atmosphere, an advanced coronagraph to block diffraction, ultrasmooth optics, a precision infrared interferometer to measure and correct systematic errors, and a integral field spectrograph/polarimeter to image and characterize target planetary systems. We predict that GPI will be able to detect planets with brightness less than 10{sup -7} of their parent star, sufficient to observe warm self-luminous planets around a large population of targets.

Authors:
; ; ; ; ; ; ; ; ; ; ; ; ; ;
Publication Date:
Research Org.:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
950621
Report Number(s):
UCRL-JRNL-230274
TRN: US0902020
DOE Contract Number:
W-7405-ENG-48
Resource Type:
Journal Article
Resource Relation:
Journal Name: Comptes rendus - Physique, vol. 8, no. 3-4, April 1, 2007, pp. 365-373; Journal Volume: 8; Journal Issue: 3-4
Country of Publication:
United States
Language:
English
Subject:
99 GENERAL AND MISCELLANEOUS; 71 CLASSICAL AND QUANTUMM MECHANICS, GENERAL PHYSICS; ACCURACY; BRIGHTNESS; CONSTRUCTION; DETECTION; DIFFRACTION; INTERFEROMETERS; OPTICS; PHOTONS; PLANETS; SOLAR SYSTEM; TARGETS

Citation Formats

Macintosh, B, Graham, J, Palmer, D, Doyon, R, Gavel, D, Larkin, J, Oppenheimer, B, Saddlemyer, L, Wallace, J K, Bauman, B, Erikson, D, Poyneer, L, Sivaramakrishnan, A, Soummer, R, and Veran, J. Adaptive Optics for Direct Detection of Extrasolar Planets: The Gemini Planet Imager. United States: N. p., 2007. Web. doi:10.1016/j.crhy.2007.04.007.
Macintosh, B, Graham, J, Palmer, D, Doyon, R, Gavel, D, Larkin, J, Oppenheimer, B, Saddlemyer, L, Wallace, J K, Bauman, B, Erikson, D, Poyneer, L, Sivaramakrishnan, A, Soummer, R, & Veran, J. Adaptive Optics for Direct Detection of Extrasolar Planets: The Gemini Planet Imager. United States. doi:10.1016/j.crhy.2007.04.007.
Macintosh, B, Graham, J, Palmer, D, Doyon, R, Gavel, D, Larkin, J, Oppenheimer, B, Saddlemyer, L, Wallace, J K, Bauman, B, Erikson, D, Poyneer, L, Sivaramakrishnan, A, Soummer, R, and Veran, J. Tue . "Adaptive Optics for Direct Detection of Extrasolar Planets: The Gemini Planet Imager". United States. doi:10.1016/j.crhy.2007.04.007. https://www.osti.gov/servlets/purl/950621.
@article{osti_950621,
title = {Adaptive Optics for Direct Detection of Extrasolar Planets: The Gemini Planet Imager},
author = {Macintosh, B and Graham, J and Palmer, D and Doyon, R and Gavel, D and Larkin, J and Oppenheimer, B and Saddlemyer, L and Wallace, J K and Bauman, B and Erikson, D and Poyneer, L and Sivaramakrishnan, A and Soummer, R and Veran, J},
abstractNote = {The direct detection of photons emitted or reflected by extrasolar planets, spatially resolved from their parent star, is a major frontier in the study of other solar systems. Direct detection will provide statistical information on planets in 5-50 AU orbits, inaccessible to current Doppler searches, and allow spectral characterization of radius, temperature, surface gravity, and perhaps composition. Achieving this will require new dedicated high-contrast instruments. One such system under construction is the Gemini Planet Imager (GPI.) This combines a high-order/high-speed adaptive optics system to control wavefront errors from the Earth's atmosphere, an advanced coronagraph to block diffraction, ultrasmooth optics, a precision infrared interferometer to measure and correct systematic errors, and a integral field spectrograph/polarimeter to image and characterize target planetary systems. We predict that GPI will be able to detect planets with brightness less than 10{sup -7} of their parent star, sufficient to observe warm self-luminous planets around a large population of targets.},
doi = {10.1016/j.crhy.2007.04.007},
journal = {Comptes rendus - Physique, vol. 8, no. 3-4, April 1, 2007, pp. 365-373},
number = 3-4,
volume = 8,
place = {United States},
year = {Tue Apr 24 00:00:00 EDT 2007},
month = {Tue Apr 24 00:00:00 EDT 2007}
}
  • During the first-light run of the Gemini Planet Imager we obtained K-band spectra of exoplanets HR 8799 c and d. Analysis of the spectra indicates that planet d may be warmer than planet c. Comparisons to recent patchy cloud models and previously obtained observations over multiple wavelengths confirm that thick clouds combined with horizontal variation in the cloud cover generally reproduce the planets' spectral energy distributions. When combined with the 3 to 4 μm photometric data points, the observations provide strong constraints on the atmospheric methane content for both planets. The data also provide further evidence that future modeling effortsmore » must include cloud opacity, possibly including cloud holes, disequilibrium chemistry, and super-solar metallicity.« less
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  • During the first-light run of the Gemini Planet Imager we obtained K-band spectra of exoplanets HR 8799 c and d. Analysis of the spectra indicates that planet d may be warmer than planet c. Comparisons to recent patchy cloud models and previously obtained observations over multiple wavelengths confirm that thick clouds combined with horizontal variation in the cloud cover generally reproduce the planets’ spectral energy distributions.When combined with the 3 to 4μm photometric data points, the observations provide strong constraints on the atmospheric methane content for both planets. Lastly, the data also provide further evidence that future modeling efforts mustmore » include cloud opacity, possibly including cloud holes, disequilibrium chemistry, and super-solar metallicity.« less
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  • The Gemini Planet Imager’s adaptive optics (AO) subsystem was designed specifically to facilitate high-contrast imaging. We give a definitive description of the system’s algorithms and technologies as built. Ultimately, the error budget indicates that for all targets and atmospheric conditions AO bandwidth error is the largest term.