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Maintaining wavefront stability while directly imaging exoplanets over long exposure times is an ongoing problem in the field of high-contrast imaging. Robust and efficient high-order wavefront sensing and control systems are required for…

Hi-5 is a high-contrast (or high dynamic range) infrared imager project for the VLTI. Its main goal is to characterize young extra-solar planetary systems and exozodiacal dust around southern main-sequence stars. In this paper, we present…

To detect Earth-like planets in the visible with a coronagraphic telescope, two major noise sources have to be overcome: the photon noise of the diffracted star light, and the speckle noise due to the star light scattered by instrumental…

Cross-correlating neutral hydrogen (HI) 21cm intensity mapping with galaxy surveys provides an effective probe of astrophysical and cosmological information. This work presents a cross-correlation analysis between MeerKAT single-dish HI…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-12 Yu-Er Jiang , Yan Gong , Qi Xiong , Wenxiang Pei , Yun Liu , Furen Deng , Zi-yan Yuwen , Meng Zhang , Xingchen Zhou , Xuelei Chen , Yin-Zhe Ma , Qi Guo , Bin Yue

Diluted arrays of many optical apertures will be able to provide h igh-resolution snapshot images if the beams are combined according to the densified-pupil scheme. We show that the same principle can also provide coronagraphic images, for…

Astrophysics · Physics 2009-10-31 A. Boccaletti , P. Riaud , C. Moutou , A. Labeyrie

Observing Earth-like exoplanets orbiting within the habitable zone of Sun-like stars and studying their atmospheres in reflected starlight requires contrasts of $\sim1\mathrm{e}{-10}$ in the visible. At such high contrast, starlight…

Earth and Planetary Astrophysics · Physics 2022-11-09 Jens Kammerer , Christopher C. Stark , Kevin J. Ludwick , Roser Juanola-Parramon , Bijan Nemati

Direct exoplanet detection is limited by speckle noise in the point spread function (PSF) of the central star. This noise can be reduced by subtracting PSF images obtained simultaneously in adjacent narrow spectral bands using a…

In strong-field physics experiments with intense lasers, it is of paramount importance to single-shot diagnose the temporal contrast between laser pulse peak and its noise pedestal. This allows fast optimization of pulse contrast and…

Optics · Physics 2021-02-26 Jingui Ma , Peng Yuan , Xiaoping Ouyang , Jing Wang , Guoqiang Xie , Liejia Qian

The Coronagraph Instrument (CGI) for NASA's Wide Field Infrared Survey Telescope (WFIRST) will constitute a dramatic step forward for high-contrast imaging, integral field spectroscopy, and polarimetry of exoplanets and circumstellar disks,…

Directly imaging and characterizing Earth-like exoplanets is a tremendously difficult instrumental challenge. Present coronagraphic systems have yet to achieve the required $10^{-10}$ broadband contrast in a laboratory environment, but…

Instrumentation and Methods for Astrophysics · Physics 2019-07-10 Carl T. Coker , Stuart B. Shaklan , A J E. Riggs , Garreth Ruane

Direct detection and spectroscopy of exoplanets requires high contrast imaging. For habitable exoplanets in particular, located at small angular separation from the host star, it is crucial to employ small inner working angle (IWA)…

Instrumentation and Methods for Astrophysics · Physics 2016-11-09 P. Pathak , O. Guyon , N. Jovanovic , J. Lozi , F. Martinache , Y. Minowa , T. Kudo , H. Takami , Y. Hayano , N. Narita

We discuss the use of parametric phase-diverse phase retrieval as an in-situ high-fidelity wavefront measurement method to characterize and optimize the transmitted wavefront of a high-contrast coronagraphic instrument. We apply our method…

Instrumentation and Methods for Astrophysics · Physics 2019-03-06 Gregory R. Brady , Christopher Moriarty , Peter Petrone , Iva Laginja , Keira Brooks , Tom Comeau , Lucie Leboulleux , Remi Soummer

Non-contrast computed tomography (NCCT) is commonly acquired for lung cancer screening, assessment of general abdominal pain or suspected renal stones, trauma evaluation, and many other indications. However, the absence of contrast limits…

Image and Video Processing · Electrical Eng. & Systems 2022-05-13 Ho Hin Lee , Yucheng Tang , Riqiang Gao , Qi Yang , Xin Yu , Shunxing Bao , James G. Terry , J. Jeffrey Carr , Yuankai Huo , Bennett A. Landman

This paper is concerned with the theoretical properties of high contrast coronagraphic images in the context of exoplanet searches. We derive and analyze the statistical properties of the residual starlight in coronagraphic images, and…

Astrophysics · Physics 2009-11-13 Rémi Soummer , André Ferrari , Claude Aime , Laurent Jolissaint

The James Webb Space Telescope (JWST) will revolutionize the field of high-contrast imaging and enable both the direct detection of Saturn-mass planets and the characterization of substellar companions in the mid-infrared. While JWST will…

The ability to accurately predict the contrast achieved from high contrast imagers is important for efficient scheduling and quality control measures in modern observatories. We aim to consistently predict and measure the raw contrast…

Instrumentation and Methods for Astrophysics · Physics 2023-12-06 Benjamin Courtney-Barre , Robert De Rosa , Rosita Kokotanekova , Cristian Romero , Matias Jones , Julien Milli , Zahed Wahhaj

The Optimal Optical CoronagraphWorkshop at the Lorentz Center in September 2017 in Leiden, the Netherlands gathered a diverse group of 25 researchers working on exoplanet instrumentation to stimulate the emergence and sharing of new ideas.…

High-contrast imaging of exoplanets and protoplanetary disks depends on wavefront sensing and correction made by adaptive optics instruments. Classically, wavefront sensing has been conducted at optical wavelengths, which made high-contrast…

For the technology development of the mission EXCEDE (EXoplanetary Circumstellar Environments and Disk Explorer) - a 0.7 m telescope equipped with a Phase-Induced Amplitude Apodization Coronagraph (PIAA-C) and a 2000-element MEMS deformable…

Instrumentation and Methods for Astrophysics · Physics 2015-06-22 Julien Lozi , Ruslan Belikov , Sandrine J. Thomas , Eugene Pluzhnik , Eduardo Bendek , Olivier Guyon , Glenn Schneider

Current and future high contrast imaging instruments aim to detect exoplanets at closer orbital separations, lower masses, and/or older ages than their predecessors. However, continually evolving speckles in the coronagraphic science image…

Instrumentation and Methods for Astrophysics · Physics 2022-06-22 Benjamin L. Gerard , Daren Dillon , Sylvain Cetre , Rebecca Jensen-Clem