相关论文: Increasing the raw contrast of VLT/SPHERE with the…

Future direct imaging missions will primarily observe planets that have been previously detected, mostly via the radial velocity (RV) technique, to characterize planetary atmospheres. In the meantime, direct imaging may discover new planets…

Combining high-contrast imaging with medium-resolution spectroscopy has been shown to significantly boost the direct detection of exoplanets. HARMONI, one of the first-light instruments to be mounted on ESO's ELT, will be equipped with a…

RISTRETTO is the evolution of the original idea of coupling the VLT instruments SPHERE and ESPRESSO \cite{lovis_2016a}, aiming at High Dispersion Coronagraphy. RISTRETTO is a visitor instrument that should enable the characterization of the…

Context. High-contrast exoplanet imaging is a rapidly growing field as can be seen through the significant resources invested. In fact, the detection and characterization of exoplanets through direct imaging is featured at all major…

The correction of quasi-static wavefront errors within a coronagraphic optical system will be a key challenge to overcome in order to directly image exoplanets in reflected light. These quasi-static errors are caused by mid to high-order…

We present a new processing technique aimed at significantly improving the angular differential imaging method (ADI) in the context of high-contrast imaging of faint objects nearby bright stars in observations obtained with extreme adaptive…

We investigate directly imaging exoplanets around eclipsing binaries, using the eclipse as a natural tool for dimming the binary and thus increasing the planet to star brightness contrast. At eclipse, the binary becomes point-like, making…

The Habitable Worlds Observatory (HWO) is a flagship mission concept proposing to characterize earth-like exoplanets at high contrast with a coronagraph instrument. The most in-depth, validated contrast error budgets made to date have been…

A multitude of coronagraphic techniques for the space-based direct detection and characterization of exo-solar terrestrial planets are actively being pursued by the astronomical community. Typical coronagraphs have internal shaped focal…

Of the over 5000 exoplanets that have been detected, only about a dozen have ever been directly imaged. Earth-like exoplanets are on the order of 10 billion times fainter than their host star in visible and near-infrared, requiring a…

The major source of noise in high-contrast imaging is the presence of slowly evolving speckles that do not average with time. The temporal stability of the point-spread-function (PSF) is therefore critical to reach a high contrast with…

Aims. We present a solution to improve the performance of coronagraphs for the detection of exo-planets. Methods. We simulate numerically several kinds of coronagraphic systems, with the aim of evaluating the gain obtained with an adaptive…

For high-contrast imaging (HCI) systems, such as VLT/SPHERE, the performance of the system at small angular separations is contaminated by the wind-driven halo in the science image. This halo is a result of the servo-lag error in the…

Over the past decades, direct imaging has confirmed the existence of substellar companions (exoplanets or brown dwarfs) on wide orbits (>10 au) from their host stars. To understand their formation and evolution mechanisms, we have initiated…

More than 450 exoplanets are known and this number increases nearly every day. Only a few constraints on their orbital parameters and physical characteristics can be determined, as most exoplanets are detected indirectly. Measuring the…

The dark-speckle method (Labeyrie 1995) combines features of speckle interferometry and adaptive optics to provide images of faint circumstellar material. We present preliminary results of observations, and simulations concluding to the…

In high-contrast imaging optical systems for direct observation of planets outside our solar system, adaptive optics with an accuracy of lambda/10,000 root mean square is required to reduce the speckle noise down to 1e-10 level in addition…

Direct imaging of exoplanets requires the detection of very faint objects orbiting close to very bright stars. In this context, the SPICES mission was proposed to the European Space Agency for planet characterization at visible wavelength.…

Small-angle coronagraphy is technically and scientifically appealing because it enables the use of smaller telescopes, allows covering wider wavelength ranges, and potentially increases the yield and completeness of circumstellar…

The search for exoplanets is pushing adaptive optics systems on ground-based telescopes to their limits. One of the major limitations at small angular separations, exactly where exoplanets are predicted to be, is the servo-lag of the…