Imaging exoplanets with coronagraphic instruments

Abstract

Exoplanetary science is a very active field of astronomy nowadays, with questions still opened such as how planetary systems form and evolve (occurrence, process), why such a diversity of exoplanets is observed (mass, radius, orbital parameters, temperature, composition), and what are the interactions between planets, circumstellar disk and their host star. Several complementary methods are used for the detection of exoplanets. Among these, imaging aims at the direct detection of the light reflected, scattered or emitted by exoplanets and circumstellar disks. This allows their spectral and polarimetric characterization. Such imaging remains challenging because of the large luminosity ratio (1e4-1e10$) and the small angular separation (fraction of an arcsecond) between the star and its environment. Over the past two decades, numerous techniques, including coronagraphy, have been developed to make exoplanet imaging a reality. This review gives a broad overview of the subsystems that make up a coronagraphic instrument for imaging exoplanetary systems. It is especially intended for non-specialists or newcomers in the field. We explain the principle of coronagraphy and propose a formalism to understand their behavior. We discuss the impact of wavefront aberrations on the performance of coronagraphs and how they induce stellar speckles in the scientific image. Finally, we present instrumental and signal processing techniques used for on-sky minimization or a posteriori calibration of these speckles in order to improve the performance of coronagraphs.

arXiv commentAccepted for publication in Comptes Rendus Physique. 48 pages (including 12 pages of references). 16 figures

References in corpus (117)

• Direct Imaging of Multiple Planets Orbiting the Star HR 8799
• Angular Differential Imaging: a Powerful High-Contrast Imaging Technique
• Images of a fourth planet orbiting HR 8799
• Detection and Characterization of Exoplanets and Disks using Projections on Karhunen-Loeve Eigenimages
• Discovery of a planetary-mass companion within the gap of the transition disk around PDS 70
• A probable giant planet imaged in the Beta Pictoris disk
• SPHERE: the exoplanet imager for the Very Large Telescope
• Discovery and spectroscopy of the young Jovian planet 51 Eri b with the Gemini Planet Imager
• A new algorithm for point spread function subtraction in high-contrast imaging: a demonstration with angular differential imaging
• The Subaru Coronagraphic Extreme Adaptive Optics system: enabling high-contrast imaging on solar-system scales
• Fundamental limitations of high contrast imaging set by small sample statistics
• PynPoint: An Image Processing Package for Finding Exoplanets
• Theoretical Limits on Extrasolar Terrestrial Planet Detection with Coronagraphs
• Limits of Adaptive Optics for high contrast imaging
• Apodized Pupil Lyot Coronagraphs for Arbitrary Telescope Apertures
• Phase-Induced Amplitude Apodization of Telescope Pupils for Extrasolar Terrestrial Planet Imaging
• A Coronagraph with a Band-Limited Mask for Finding Terrestrial Planets
• High-contrast Imaging from Space: Speckle Nulling in a Low Aberration Regime
• Discovery of a warm, dusty giant planet around HIP65426
• Impact of angular differential imaging on circumstellar disk images
• Detection and Characterization of Exoplanets using Projections on Karhunen-Loeve Eigenimages: Forward Modeling
• Images of Embedded Jovian Planet Formation At A Wide Separation Around AB Aurigae
• Calibration of quasi-static aberrations in exoplanet direct-imaging instruments with a Zernike phase-mask sensor
• Optimal Dark Hole Generation via Two Deformable Mirrors with Stroke Minimization
• High Dynamic Range Imaging Using a Deformable Mirror for Space Coronography
• The Structure of High Strehl Ratio Point-Spread Functions
• The Habitable Exoplanet Observatory (HabEx) Mission Concept Study Final Report
• Review of small-angle coronagraphic techniques in the wake of ground-based second-generation adaptive optics systems
• Direct exoplanet detection and characterization using the ANDROMEDA method: Performance on VLT/NaCo data
• Confirmation of the planet around HD 95086 by direct imaging
• High Performance Lyot and PIAA Coronagraphy for Arbitrarily shaped Telescope Apertures
• Astrometric and photometric accuracies in high contrast imaging: The SPHERE speckle calibration tool (SpeCal)
• The HOSTS survey for exozodiacal dust: Observational results from the complete survey
• Temporal Evolution of Coronagraphic Dynamic Range, and Constraints on Companions to Vega
• The LUVOIR Mission Concept Study Final Report
• On-sky speckle nulling demonstration at small angular separation with SCExAO
• Imaging extrasolar planets by stellar halo suppression in separately-corrected color bands
• First images of debris disks around TWA 7, TWA 25, HD 35650, and HD 377
• Very high contrast IFU spectroscopy of AB Doradus C: 9 mag contrast at 0.2" without a coronagraph using spectral deconvolution
• The Mid-Infrared Instrument for the James Webb Space Telescope, V: Predicted Performance of the MIRI Coronagraphs
• Design, analysis and test of a microdots apodizer for the Apodized Pupil Lyot Coronagraph
• High Contrast Imaging with an Arbitrary Aperture: Active Correction of Aperture Discontinuities
• The Vector-APP: a Broadband Apodizing Phase Plate that yields Complementary PSFs
• Modeling Self-Subtraction in Angular Differential Imaging: Application to the HD 32297 Debris Disk
• Ring-apodized vortex coronagraphs for obscured telescopes. I. Transmissive ring apodizers
• First On-Sky High Contrast Imaging with an Apodizing Phase Plate
• The SPHERE infrared survey for exoplanets (SHINE) -- II. Observations, Data reduction and analysis Detection performances and early-results
• Apodized pupil Lyot coronagraphs for arbitrary apertures. V. Hybrid Shaped Pupil designs for imaging Earth-like planets with future space observatories
• The Asymmetric Pupil Fourier Wavefront Sensor
• Lyot-based Low Order Wavefront Sensor for Phase-mask Coronagraphs: Principle, Simulations and Laboratory Experiments
• Shaped Pupil Lyot Coronagraphs: High-Contrast Solutions for Restricted Focal Planes
• Post-coronagraphic tip-tilt sensing for vortex phase masks: the QACITS technique
• Self-coherent camera as a focal plane wavefront sensor: simulations
• Calibration of quasi-static aberrations in exoplanet direct-imaging instruments with a Zernike phase-mask sensor. III. On-sky validation in VLT/SPHERE
• A search for a 5th planet around HR 8799 using the star-hopping RDI technique at VLT/SPHERE
• The coronagraphic Modal Wavefront Sensor: a hybrid focal-plane sensor for the high-contrast imaging of circumstellar environments
• Estimation and correction of wavefront aberrations using the self-coherent camera: laboratory results
• Speckle temporal stability in XAO coronagraphic images II. Refine model for quasi-static speckle temporal evolution for VLT/SPHERE
• Lyot Coronagraphy on Giant Segmented-Mirror Telescopes
• Differential Imaging with a Multicolor Detector Assembly: A New ExoPlanet Finder Concept
• Prototyping coronagraphs for exoplanet characterization with SPHERE
• Speckle suppression and companion detection using coherent differential imaging
• An Eight-Octant Phase-Mask Coronagraph
• Multiband GPI Imaging of the HR 4796A Debris Disk
• Active correction of aperture discontinuities - optimized stroke minimization II: optimization for future missions
• Coronagraphic phase diversity: performance study and laboratory demonstration
• Multiband Polarimetric Imaging of HR 4796A with the Gemini Planet Imager
• REXPACO: an algorithm for high contrast reconstruction of the circumstellar environment by angular differential imaging
• Focal plane wavefront sensor achromatization : The multireference self-coherent camera
• The vector-apodizing phase plate coronagraph: design, current performance, and future development
• Clio: a 3-5 micron AO planet-finding camera
• Apodized phase mask coronagraphs for arbitrary apertures
• Improved achromatization of phase mask coronagraphs using colored apodization
• Experimental demonstration of binary shaped pupil mask coronagraphs for telescopes with obscured pupils
• Minimizing the polarization leakage of geometric-phase coronagraphs with multiple grating pattern combinations
• High-Contrast Testbeds for Future Space-Based Direct Imaging Exoplanet Missions
• Comparing focal plane wavefront control techniques:\\Numerical simulations and laboratory experiments
• Focal-plane wavefront sensing with the vector Apodizing Phase Plate
• A Family of Phase Masks For Broadband Coronagraphy Example of the Wrapped Vortex Phase Mask Theory and Laboratory demonstration
• Lyot-plane phase masks for improved high-contrast imaging with a vortex coronagraph
• An analytic expression for coronagraphic imaging through turbulence. Application to on-sky coronagraphic phase diversity
• SPHERE+: Imaging young Jupiters down to the snowline
• Multi-stage four-quadrant phase mask: achromatic coronagraph for space-based and ground-based telescopes
• Polynomial Apodizers for Centrally Obscured Vortex Coronagraphs
• Active correction of aperture discontinuities - optimized stroke minimization I: a new adaptive interaction matrix algorithm
• Dark Hole Maintenance and A Posteriori Intensity Estimation in the Presence of Speckle Drift in a High-Contrast Space Coronagraph
• Increasing the raw contrast of VLT/SPHERE with the dark hole technique. I. Simulations and validation on the internal source
• Analytical tolerancing of segmented telescope co-phasing for exo-Earth high-contrast imaging
• Laboratory validation of the dual-zone phase mask coronagraph in broadband light at the high-contrast imaging THD-testbed
• Paving the Way to Future Missions: the Roman Space Telescope Coronagraph Technology Demonstration
• Experimental validation of joint phase and amplitude wave-front sensing with coronagraphic phase diversity for high-contrast imaging
• Scalar vortex coronagraph mask design and predicted performance
• Apodized vortex coronagraph designs for segmented aperture telescopes
• Phase-Apodized-Pupil Lyot Coronagraphs for Arbitrary Telescope Pupils
• Review of high-contrast imaging systems for current and future ground- and space-based telescopes I. Coronagraph design methods and optical performance metrics
• Fast Coherent Differential Imaging on Ground-Based Telescopes using the Self-Coherent Camera
• Increasing the raw contrast of VLT/SPHERE with the dark-hole technique. II. On-sky wavefront correction and coherent differential imaging
• Diffraction-Based Sensitivity Analysis of Apodized Pupil Mapping Systems
• Calibration of quasi-static aberrations in exoplanet direct-imaging instruments with a Zernike phase-mask sensor. IV. Temporal stability of non-common path aberrations in VLT/SPHERE
• Direct imaging of exoplanets: Legacy and prospects
• Active minimization of non-common path aberrations in long-exposure imaging of exoplanetary systems
• Implementing focal-plane phase masks optimized for real telescope apertures with SLM-based digital adaptive coronagraphy
• DiskFM: A Forward Modeling Tool for Disk Analysis with Coronagraphic Instruments
• Minimization of non common path aberrations at the Palomar telescope using a self-coherent camera
• A Binary Shaped Mask Coronagraph for a Segmented Pupil
• 10^{-7} contrast ratio at 4.5Lambda/D: New results obtained in laboratory experiments using nano-fabricated coronagraph and multi-Gaussian shaped pupil masks
• First on-sky demonstration of spatial Linear Dark Field Control with the vector-Apodizing Phase Plate at Subaru/SCExAO
• High Contrast Imaging with Gaussian Aperture Pupil Masks (GAPMs)
• Laboratory Demonstration of Spatial Linear Dark Field Control For Imaging Extrasolar Planets in Reflected Light
• The polarization-encoded self-coherent camera
• Information-theoretical Limits of Recursive Estimation and Closed-loop Control in High-contrast Imaging
• SLM-based Active Focal-Plane Coronagraphy: Status and future on-sky prospects
• High contrast at small separation -- II. Impact on the dark hole of a realistic optical set-up with two deformable mirrors
• Fundamental limits to high-contrast wavefront control
• Apodized Pupil Lyot Coronagraphs with arbitrary aperture telescopes: novel designs using hybrid focal plane masks
• The Mysterious Lives Of Speckles. I. Residual atmospheric speckle lifetimes in ground-based coronagraphs
• Peering through SPHERE Images: A Glance at Contrast Limitations

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• Direct imaging of exoplanets: Legacy and prospects
• The COBREX archival survey: improved constraints on the occurrence rate of wide-orbit substellar companions. I. A uniform re-analysis of 400 stars from the GPIES survey
• High-order wavefront sensing and control for the Roman Coronagraph Instrument (CGI): architecture and measured performance
• Cascade adaptive optics with a second stage based on a Zernike wavefront sensor for exoplanet observations
• Machine learning for exoplanet detection in high-contrast spectroscopy Combining cross correlation maps and deep learning on medium-resolution integral-field spectra
• Asgard/NOTT: L-band nulling interferometry at the VLTI -- III. The mid-infrared integrated optics beam combiner for NOTT
• Performance Calibration of the Wavefront Sensor's EMCCD Detector for the Cool Planets Imaging Coronagraph Aboard CSST
• The Effects of Binary Reference Stars on JWST NIRCam Coronagraphy