Orbital Differential Imaging: a new high-contrast post-processing technique for direct imaging of exoplanets

Males, Jared R.; Belikov, Ruslan; Bendek, Eduardo

doi:10.1117/12.2188766

Cited by 9 publications

(11 citation statements)

References 8 publications

(9 reference statements)

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“…But, if pseudo-static speckles are still present after ADI reduction, it is probably possible to use a Keplerien-ADI method to remove them. Where ADI uses the parallactic rotation to differentiate speckles from planets, Keplerian-ADI instead uses the orbital motion such as proposed by Males et al (2015) with their ODI technique. But, Keplerian-ADI can be used with any set of orbital parameters (long, or short periods, eccentric, etc.)…”

Section: Discussionmentioning

confidence: 99%

K-Stacker, a new way of detecting and characterizing exoplanets with high contrast imaging instruments

Coroller,

Nowak,

Arnold

et al. 2015

Preprint

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This year, a second generation of coronagraphs dedicated to high-contrast direct imaging of exoplanets is starting operations. Among them, SPHERE, installed at the focus of the UT3 Very Large Telescope, reaches unprecedented contrast ratios up to 10 −6 -10 −7 , using eXtreme Adaptive Optics and the Angular Differential Imaging (ADI) techniques. In this paper, we present a new method called Keplerian-Stacker that improves the detection limit of high contrast instruments like SPHERE, by up to a factor of 10. It consists of observing a star on a long enough period to let a hypothetical planet around that star move along its orbit. Even if in each individual observation taken during one night, we do not detect anything, we show that it is possible, using an optimization algorithm, to re-center the images according to keplerian motions (ex: 10-100 images taken over a long period of typically 1-10 years) and detect planets otherwise unreachable. This method can be used in combination with the ADI technics (or possibly any other high contrast data reduction method) to improve the Signal to Noise Ratio in each individual image, and to further improve the global detection limit. It also directly provides orbital parameters of the detected planets, as a by-product of the optimization algorithm.

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Section: Discussionmentioning

confidence: 99%

K-Stacker, a new way of detecting and characterizing exoplanets with high contrast imaging instruments

Coroller,

Nowak,

Arnold

et al. 2015

Preprint

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“…This is the motivation behind our on-going LBTI Exploratory Survey for Super-Earths Orbitng Nearby Stars (LESSONS). These observations will also demonstrate the ability to combine data from multiple nights and will test new data reduction methods for handling orbital motion [e.g., 55,56]. Finally, ‡ While all of these would be detectable over multiple epochs, a single observation may miss some highly-inclined planets that are in close projected separation to their stars.…”

Section: Exoplanet Science With High-contrast Mid-ir Imagingmentioning

confidence: 99%

Imaging low-mass planets within the habitable zones of nearby stars with ground-based mid-infrared imaging

Wagner¹,

Stone²,

Leisenring³

et al. 2021

Preprint

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Giant exoplanets on 10-100 au orbits have been directly imaged around young stars. The peak of the thermal emission from these warm young planets is in the near-infrared (∼1-5 µm), whereas mature, temperate exoplanets (i.e., those within their stars' habitable zones) radiate primarily in the mid-infrared (mid-IR: ∼10 µm). If the background noise in the mid-IR can be mitigated, then exoplanets with low masses-including rocky exoplanets-can potentially be imaged in very deep exposures. Here, we review the recent results of the Breakthrough Watch/New Earths in the Alpha Centauri Region (NEAR) program on the Very Large Telescope (VLT) in Chile. NEAR pioneered a ground-based mid-IR observing approach designed to push the capabilities for exoplanet imaging with a specific focus on the closest stellar system, α Centauri. NEAR combined several new optical technologies-including a mid-IR optimized coronagraph, adaptive optics system, and rapid chopping strategy to mitigate noise from the central star and thermal background within the habitable zone. We focus on the lessons of the VLT/NEAR campaign to improve future instrumentation−specifically on strategies to improve noise mitigation through chopping. We also present the design and commissioning of the Large Binocular Telescope's Exploratory Survey for Super-Earths Orbiting Nearby Stars (LESSONS), an experiment in the Northern hemisphere that is building on what was learned from NEAR to further push the sensitivity of mid-IR imaging. Finally, we briefly discuss some of the possibilities that mid-IR imaging will enable for exoplanet science.

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“…All the bands will be imaged simultaneously, however only one band will be actively controlled by the DM at a time. Nuvu manufactures cameras based on the EMCCD 201-20 detector [16] and provides a controller that achieve the desired performance ( Fig. 8) The same system has been selected for the AFTA-C mission and a technology development effort with Nuvu, the Center for Electronic Imaging, and First Light Imaging have commenced to bring these detectors to TRL-6 by January 2016.…”

Section: Science Detector (Sd) and Dichroic Systemmentioning

confidence: 99%

Section: Science Detector (Sd) and Dichroic Systemmentioning

confidence: 99%

Space telescope design to directly image the habitable zone of Alpha Centauri

et al. 2015

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The scientific interest in directly image and identifying Earth-like planets within the Habitable Zone (HZ) around nearby stars is driving the design of specialized direct imaging mission such as ACESAT, EXO-C, EXO-S and AFTA-C. The inner edge of Alpha Cen A&B Habitable Zone is found at exceptionally large angular separations of 0.7" and 0.4" respectively. This enables direct imaging of the system with a 0.3m class telescope. Contrast ratios in the order of 10 10 are needed to image Earth-brightness planets. Low-resolution (5-band) spectra of all planets, will allow establishing the presence and amount of an atmosphere. This star system configuration is optimal for a specialized small, and stable space telescope, that can achieve high-contrast but has limited resolution. This paper describes an innovative instrument design and a mission concept based on a full Silicon Carbide off-axis telescope, which has a Phase Induce Amplitude Apodization coronagraph embedded in the telescope. This architecture maximizes stability and throughput. A Multi-Star Wave Front algorithm is implemented to drive a deformable mirror controlling simultaneously diffracted light from the on-axis and binary companion star. The instrument has a Focal Plane Occulter to reject starlight into a highprecision pointing control camera. Finally we utilize a Orbital Differential Imaging (ODI) post-processing method that takes advantage of a highly stable environment (Earth-trailing orbit) and a continuous sequence of images spanning 2 years, to reduce the final noise floor in post processing to ~2e-11 levels, enabling high confidence and at least 90% completeness detections of Earth-like planets.Objective 1.1. Directly image planets in the region around αCen A&B from the inner HZ edge out to the dynamical stability limit, with >90% completeness down to Earth brightness Objective 1.2: Directly image a debris disk around αCen A and αCen B if one exists, (down to 1 zodi variations). A thick or more dense debris disk scatters starlight decreasing the plant contrast with background and requiring more signals for the detection. Objective 2.1. Determine the orbits of planets found in obj. 1.1. by fitting a keplerian motion to the detected source over time. Objective 2.2. Constrain the size and mass of planets. The dataset for this objective is the same as for objective 1.1, except that the reflectivity as a function of wavelength can be used to help constrain planet size. Figure 1: Apparent configuration of the αCen A&B system as seen from the earth. The disk on the left represents αCen A and the one on the right is αCen B. The HZ of each star is shown in green and light green to represent the classical and extended HZ.

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Orbital Differential Imaging: a new high-contrast post-processing technique for direct imaging of exoplanets

Cited by 9 publications

References 8 publications

K-Stacker, a new way of detecting and characterizing exoplanets with high contrast imaging instruments

K-Stacker, a new way of detecting and characterizing exoplanets with high contrast imaging instruments

Imaging low-mass planets within the habitable zones of nearby stars with ground-based mid-infrared imaging

Space telescope design to directly image the habitable zone of Alpha Centauri

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