Theoretical Limits on Extrasolar Terrestrial Planet Detection with Coronagraphs

By Olivier Guyon, E. Pluzhnik, M. Kuchner, Benoît Collins, S. Ridgway. 2006

356 citations recorded by the source corpus.

Many high-contrast coronagraph designs have recently been proposed. In this paper, their suitability for direct imaging of extrasolar terrestrial planets is reviewed. We also develop a linear algebra based model of coronagraphy that can both explain the behavior of existing coronagraphs and quantify the coronagraphic performance limit imposed by fundamental physics. We find that the maximum theoretical throughput of a coronagraph is equal to 1 minus the nonaberrated noncoronagraphic PSF of the telescope. We describe how a coronagraph reaching this fundamental limit may be designed, and how much improvement over the best existing coronagraph design is still possible. Both the analytical model and numerical simulations of existing designs also show that this theoretical limit rapidly degrades as the source size is increased: the "highest performance" coronagraphs, those with the highest throughput and smallest inner working angle (IWA), are the most sensitive to stellar angular diameter. This unfortunately rules out the possibility of using a small IWA (<λ/d) coronagraph for a terrestrial planet imaging mission. Finally, a detailed numerical simulation that accurately accounts for stellar angular size, zodiacal and exozodiacal light is used to quantify the efficiency of coronagraph designs for direct imaging of extrasolar terrestrial planets in a possible real observing program. We find that in the photon noise-limited regime, a 4 m telescope with a theoretically optimal coronagraph is able to detect Earth-like planets around 50 stars with 1 hr exposure time per target (assuming 25% throughput and exozodi levels similar to our solar system). We also show that at least two existing coronagraph design can approach this level of performance in the ideal monochromatic case considered in this study.

Subfields: Astronomy and Astrophysics, Atomic and Molecular Physics, and Optics, Biomedical Engineering

View Paper: https://www.semanticscholar.org/paper/43b35eb11577e5aefcba8d32c14725a9602140b8

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

1. B. Bowler
2. H. Schwarz
3. I. Snellen
4. J. Birkby
5. Remco J. de Kok
6. M. Brogi
7. L. Pueyo
8. A. Vigan

In Atomic and Molecular Physics, and Optics

1. B. Bowler
2. I. Snellen
3. L. Pueyo
4. C. Marois
5. N. Madhusudhan

In Biomedical Engineering

1. B. Bowler

Citations in the corpus

• Imaging Extrasolar Giant Planets (2016, background): “…& Casewell 2014; Madhusudhan et al. 2014; Quanz 2015; Crossfield 2015), and high contrast imaging instruments and speckle suppression techniques (Guyon et al. 2006; Beuzit et al. 2007; Oppenheimer & Hinkley 2009; Biller et al. 2008; Marois et al. 2010a; Traub & Oppenheimer 2010; Mawet et al.…”
• THE LINK BETWEEN PLANETARY SYSTEMS, DUSTY WHITE DWARFS, AND METAL-POLLUTED WHITE DWARFS (2012, background): “Limits on the masses of these types of planetesimal belts will be useful for constraining how dusty main sequence stars are in the terrestrial planet forming regions, a crucial measurement to determine how successful terrestrial planet imaging missions in the future might be (Guyon et al. 2006).”
• FUNDAMENTAL LIMITATIONS OF HIGH CONTRAST IMAGING SET BY SMALL SAMPLE STATISTICS (2014, background): “…to the diffraction limit of the telescope (IWA= 1λ/D, i.e. one resolution element, with λ and D, the wavelength and telescope diameter, respectively) with sufficient throughput (∼ 50%, see Guyon et al. (2006), or Mawet et al. (2012) for a more recent survey of small angle coronagraphic techniques).”
• SPHERE: the exoplanet imager for the Very Large Telescope (2019, background): “Focal masks can be opaque, semi-transparent, or based on a phase pattern with various geometries, or a combination of amplitude and phase (see Guyon et al. 2006, for a review).”
• THE VECTOR VORTEX CORONAGRAPH: LABORATORY RESULTS AND FIRST LIGHT AT PALOMAR OBSERVATORY (2009, background): “Image dynamic ranges can be increased with a coronagraph, and in a comparison of coronagraphs, Guyon et al. (2006) identified two as closest to theoretically ideal in terms of “useful throughput”: the phase-induced amplitude apodization coronagraph, and the optical vortex phase-mask coronagraph…”
• Combining high-dispersion spectroscopy with high contrast imaging : Probing rocky planets around our nearest neighbors (2015, background): “Coronagraphs are angular filters that reject on-axis light whilst transmitting light from nearby off-axis faint companions, reducing the diffraction halo from the primary star through optics introduced in the focal plane and pupil planes of the science camera (see Guyon et al. 2006a for a review).”