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Directly imaging Earth-sized exoplanets with a visible-light coronagraph instrument on a space telescope will require a system that can achieve $\sim10^{-10}$ raw contrast and maintain it for the duration of observations (on the order of…

Differential imaging is a postprocessing method to obtain high contrast, often used for exoplanet searches. The coherent differential imaging on speckle area nulling (CDI-SAN) method was developed to detect a faint exoplanet lying beneath…

Instrumentation and Methods for Astrophysics · Physics 2022-05-25 Jun Nishikawa

HiCAT is a high-contrast imaging testbed designed to provide complete solutions in wavefront sensing, control and starlight suppression with complex aperture telescopes. The pupil geometry of such observatories includes primary mirror…

We present a new high-contrast imaging testbed designed to provide complete solutions in wavefront sensing, control and starlight suppression with complex aperture telescopes. The testbed was designed to enable a wide range of studies of…

NASA's Habitable Worlds Observatory (HWO) concept and the 2020 Decadal Survey's recommendation to develop a large space telescope to "detect and characterize Earth-like extrasolar planets" requires new starlight suppression technologies to…

Context. In the context of direct imaging of exoplanets, coronagraphs are commonly proposed to reach the required very high contrast levels. However, wavefront aberrations induce speckles in their focal plane and limit their performance.…

Instrumentation and Methods for Astrophysics · Physics 2015-06-18 Johan Mazoyer , Pierre Baudoz , Raphaël Galicher , Gérard Rousset

Context. Direct imaging of exoplanets takes advantage of state-of-the-art adaptive optics (AO) systems, coronagraphy, and post-processing techniques. Coronagraphs attenuate starlight to mitigate the unfavorable flux ratio between an…

Instrumentation and Methods for Astrophysics · Physics 2022-09-21 Axel Potier , Johan Mazoyer , Zahed Wahhaj , Pierre Baudoz , Gael Chauvin , Raphael Galicher , Garreth Ruane

High-dispersion coronagraphy (HDC) optimally combines high contrast imaging techniques such as adaptive optics/wavefront control plus coronagraphy to high spectral resolution spectroscopy. HDC is a critical pathway towards fully…

Imaging planets in reflected light, a key focus of future NASA missions and ELTs, requires advanced wavefront control to maintain a deep, temporally correlated null of stellar halo -- i.e. a dark hole -- at just several diffraction beam…

Simultaneous spectral differential imaging is a high contrast technique by which subtraction of simultaneous images reduces noise from atmospheric speckles and optical aberrations. Small non-common wave front errors between channels can…

Astrophysics · Physics 2009-11-10 C. Marois , R. Racine , R. Doyon , D. Lafreniere , D. Nadeau

Context: The detection and characterization of Earth-like exoplanets (exoEarths) from space requires exquisite wavefront stability at contrast levels of $10^{-10}$. On segmented telescopes in particular, aberrations induced by cophasing…

The High Contrast spectroscopy testbed for Segmented Telescopes (HCST) is being developed at Caltech. It aims at addressing the technology gap for future exoplanet imagers and providing the U.S. community with an academic facility to test…

Instrumentation and Methods for Astrophysics · Physics 2018-07-19 N. Jovanovic , G. Ruane , D. Echeverri , J. R. Delorme , D. Mawet , J. Fucik , J. K. Wallace , C. Coker , A. Delacroix , N. Levraud , J. D. ~Llop~Sayson , J. Wang , R. Riddle , M. A. Millar-Blanchaer

Imaging exoplanetary systems is essential to characterizing exoplanetary systems and to studying planet-disk interactions to understand planet formation. Such imaging in the visible and near-infrared is challenging because these objects are…

Instrumentation and Methods for Astrophysics · Physics 2024-03-29 Raphael Galicher , Axel Potier , Johan Mazoyer , Zahed Wahhaj , Pierre Baudoz , Gaël Chauvin

The development of spaceborne coronagraphic technology is of paramount importance to the detection of habitable exoplanets in visible light. In space, coronagraphs are able to bypass the limitations imposed by the atmosphere to reach deeper…

In a standard computed tomography (CT) image, pixels having the same Hounsfield Units (HU) can correspond to different materials and it is therefore challenging to differentiate and quantify materials. Dual-energy CT (DECT) is desirable to…

Medical Physics · Physics 2020-10-27 Wei Zhao , Tianling Lyu , Yang Chen , Lei Xing

We conducted a number of multi-band coronagraph experiments using a vacuum chamber and a binary-shaped pupil mask which in principle should work at all wavelengths, in the context of the research and development on a coronagraph to observe…

Instrumentation and Methods for Astrophysics · Physics 2015-05-28 Kanae Haze , Keigo Enya , Lyu Abe , Takayuki Kotani , Takao Nakagawa , Toshimichi Sato , Tomoyasu Yamamuro

This paper presents the setup for empirical validations of the Pair-based Analytical model for Segmented Telescope Imaging from Space (PASTIS) tolerancing model for segmented coronagraphy. We show the hardware configuration of the…

Polarization aberrations originating from the telescope and high-contrast imaging instrument optics introduce polarization-dependent speckles and associated errors in the image plane, affecting the measured exoplanet signal. Understanding…

Instrumentation and Methods for Astrophysics · Physics 2024-06-28 Ramya M Anche , Kyle J. Van Gorkom , Jaren N. Ashcraft , Ewan Douglas , Emory L Jenkins , Sebastiaan Y. Haffert , Maxwell A. Millar-Blanchaer

Direct imaging of exoplanets presents a formidable technical challenge owing to the small angular separation and high contrast between exoplanets and their host stars. High Dispersion Coronagraphy (HDC) is a pathway to achieve unprecedented…

Earth and Planetary Astrophysics · Physics 2017-04-05 Ji Wang , Dimitri Mawet , Garreth Ruane , Renyu Hu , Bjorn Benneke

The 2020 Decadal Survey on Astronomy and Astrophysics tasked future space observatories with the goal of detecting and characterizing a large sample of Earth-like exoplanets. To achieve this, these observatories will require coronagraphs…