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Related papers: Improved Contrast in Images of Exoplanets using Di…

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In direct imaging at high contrast, the bright glare produced by the host star makes the detection and the characterization of sub-stellar companions particularly challenging. In spite of the use of an extreme adaptive optics system…

Instrumentation and Methods for Astrophysics · Physics 2024-09-23 Olivier Flasseur , Théo Bodrito , Julien Mairal , Jean Ponce , Maud Langlois , Anne-Marie Lagrange

We discuss the preliminary results of a survey of young (<300 Myr), close (<50 pc) stars with the Simultaneous Differential Extrasolar Planet Imager (SDI) implemented at the VLT and the MMT. SDI uses a double Wollaston prism and a quad…

The current direct observations of brown dwarfs and exoplanets have been obtained using instruments not specifically designed for overcoming the large contrast ratio between the host star and any wide-separation faint companions. However,…

Instrumentation and Methods for Astrophysics · Physics 2015-06-03 Sasha Hinkley

In this paper a homomorphic filtering scheme is proposed to improve the estimation of the planet/star radius ratio in astronomical transit signals. The idea is to reduce the effect of the short-term earth atmosphere variations. A two-step…

Instrumentation and Methods for Astrophysics · Physics 2017-10-03 Rodrigo Mahu , Patricio Rojo , Ali Dehghan Firoozabadi , Ismael Soto , Elyar Sedaghati , Nestor Becerra Yoma

Context: JWST has enabled transmission spectroscopy at unprecedented precision, but stellar heterogeneities (spots and faculae) remain a dominant contamination source that can bias atmospheric retrievals if uncorrected. Aims: We present a…

Earth and Planetary Astrophysics · Physics 2026-02-13 David S. Duque-Castaño , Lauren Flor-Torres , Jorge I. Zuluaga

The non-destructive readout mode of a detector allows its pixels to be read multiple times during integration, generating a series of "up-the-ramp" images that keep accumulating photons between successive frames. Since the noise is…

Instrumentation and Methods for Astrophysics · Physics 2025-01-16 Guanghuan Wang , Hu Zhan , Zun Luo , Chengqi Liu , Youhua Xu , Chun Lin , Yanfeng Wei , WenLong Fan

We present a method that allows us for the first time to estimate the signal-to-noise ratio (SNR) of the harmonic-space galaxy bispectrum induced by gravity, a complementary probe to already well established Fourier-space clustering…

Cosmology and Nongalactic Astrophysics · Physics 2021-01-08 Francesco Montanari , Stefano Camera

Imaging the direct light signal from a faint exoplanet against the overwhelming glare of its host star presents one of the fundamental challenges to modern astronomical instrumentation. Achieving sufficient signal-to-noise for detection by…

Instrumentation and Methods for Astrophysics · Physics 2014-03-05 S. Lacour , P. Tuthill , J. D. Monnier , T. Kotani , L. Gauchet , P. Labeye

The Rayleigh limit and low Signal-to-Noise Ratio (SNR) scenarios pose significant limitations to optical imaging systems used in remote sensing, infrared thermal imaging, and space domain awareness. In this study, we introduce a Stochastic…

Optics · Physics 2024-01-18 Hyunsoo Choi , Seungman Choi , Peter Menart , Angshuman Deka , Zubin Jacob

We present an algorithm that uses the distribution of photon arrival times to distinguish speckles from incoherent sources, like planets and disks, in high contrast images. Using simulated data, we show that our approach can overcome the…

Instrumentation and Methods for Astrophysics · Physics 2019-10-09 Alex B. Walter , Clinton Bockstiegel , Timothy D. Brandt , Benjamin A. Mazin

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

Image subtraction in astronomy is a tool for transient object discovery and characterization, particularly useful in wide fields, and is well suited for moving or photometrically varying objects such as asteroids, extra-solar planets and…

Instrumentation and Methods for Astrophysics · Physics 2013-01-09 Steven Hartung

In the two decades since the first extra-solar planet was discovered, the detection and characterization of extra-solar planets has become one of the key endeavors in all of modern science. Recently direct detection techniques such as…

Context. Several exoplanet direct imaging instruments will soon be in operation. They use an extreme adaptive optics (XAO) system to correct the atmospheric turbulence and provide a highly-corrected beam to a near-infrared (NIR) coronagraph…

Instrumentation and Methods for Astrophysics · Physics 2015-06-16 M. N'Diaye , K. Dohlen , T. Fusco , B. Paul

Direct detection is a very promising field in exoplanet science. It allows the detection of companions with large separation and allows their spectral analysis. A few planets have already been detected and are under spectral analysis. But…

Instrumentation and Methods for Astrophysics · Physics 2017-10-11 Johan Mazoyer , Raphaël Galicher , Pierre Baudoz , Gérard Rousset

We research the requirements of High Contrast Imaging when combined with the cross correlation (CC) of high resolution spectra with known spectroscopic templates for detecting and characterising exoplanets in reflected light. We simulate…

Earth and Planetary Astrophysics · Physics 2019-02-13 George A. Hawker , Ian R. Parry

The Keck Planet Imager and Characterizer (KPIC), a series of upgrades to the Keck II Adaptive Optics System and Instrument Suite, aims to demonstrate high-resolution spectroscopy of faint exoplanets that are spatially resolved from their…

Spectral retrieval techniques are currently our best tool to interpret the observed exoplanet atmospheric data. Said techniques retrieve the optimal atmospheric components and parameters by identifying the best fit to an observed…

Earth and Planetary Astrophysics · Physics 2020-10-21 Kai Hou Yip , Ingo P. Waldmann , Angelos Tsiaras , Giovanna Tinetti

To date, infrared interferometry at best achieved contrast ratios of a few times $10^{-4}$ on bright targets. GRAVITY, with its dual-field mode, is now capable of high contrast observations, enabling the direct observation of exoplanets. We…

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