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Last name: VIGAN
First name: Arthur
In the spirit of Bernard Lyot: the direct detection of planets and circumstellar disks in the 21st century, ed. P. Kalas, n/a, (2007)
The search for biosignatures in potentially habitable exoplanets is one of the major astrophysics' drivers for the coming decades, and the prime science goal of the HWO NASA mission, a large UV-Optical-IR space telescope to be launched in the 2040s. To reach this goal, it will be equipped with state-of-the-art high-contrast spectroimaging...
Context. Segmented aperture telescopes require an alignment procedure with successive steps from coarse alignment to monitoring process in order to provide very high optical quality images for stringent science operations such as exoplanet imaging. The final step, referred to as fine phasing, calls for a high sensitivity wavefront sensing and...
In this study, we explored the fundamental contrast limit of NIRCam coronagraphy observations, representing the achievable performance with post-processing techniques. This limit is influenced by photon noise and readout noise, with complex noise propagation through post-processing methods like principal component analysis. We employed two...
International audience
Exoplanet imaging with ELTs: exploring a second-stage AO with a Zernike wavefront sensor on the ESO/GHOST testbed
The Roman Space Telescope will be a critical mission to demonstrate high-contrast imaging technologies allowing for the characterisation of exoplanets in reflected light. It will demonstrate 10 -7 contrast limits or better at 3-9 λ/D separations with active wavefront control for the first time in space. The detection limits for the Coronagraph...
The Zernike wavefront sensor (ZWFS) is a concept belonging to the wide class Fourier-filtering wavefront sensor (FFWFS). The ZWFS is known for its extremely high sensitivity while having a low dynamic range, which makes it a unique sensor for second stage adaptive optics (AO) systems or quasi-static aberrations calibration sensor. This sensor...
SPHERE (Spectro-Polarimetric High-contrast Exoplanet REsearch) is the second-generation VLT instrument devoted primarily to direct imaging and characterization of exoplanets, and allowing a large number of promising observation modes. In this framework, an IDL-based end-to-end numerical tool has been developed within the problem-solving...
Context. Since 1995 and the first discovery of an exoplanet orbiting a main-sequence star, 4000 exoplanets have been discovered using several techniques. However, only a few of these exoplanets were detected through direct imaging. Indeed, the imaging of circumstellar environments requires high-contrast imaging facilities and accurate control...
Radio and near-infrared observations have observed dozens of protoplanetary disks that host spiral arm features. Numerical simulations have shown that companions may excite spiral density waves in protoplanetary disks via companion-disk interaction. However, the lack of direct observational evidence for spiral-driving companions poses...
Circumstellar environments are now routinely observed by dedicated high-contrast imagers on large, ground-based observatories. These facilities combine extreme adaptive optics and coronagraphy to achieve unprecedented sensitivities for exoplanet detection and spectral characterization. However, non-common path aberrations (NCPA) in these...
Proxima b is a rocky exoplanet in the habitable zone of the nearest star system and a key test case in the search for extraterrestrial life. Here, we investigate the characterization of a potential Earth-like atmosphere around Proxima b in reflected light via molecule mapping, combining high-resolution spectroscopy (HRS) and high contrast...
In the context of the SPHERE planet finder project, we further develop and characterize a recently proposed method for the efficient direct detection of exoplanets from the ground using spectral and angular differential imaging. The method, called ANDROMEDA, combines images appropriately into "pseudo-data", then uses all of them in a...
International audience
SPHERE is a second generation instrument for the Very Large Telescope (VLT) which will aim at directly detecting the intrinsic flux of young giant exoplanets thanks to a dedicated extreme adaptive optics system and coronagraphs. Exoplanet detection in the near-infrared will be performed in parallel with an integral field spectrograph and a...
International audience
International audience
International audience
Imaging exo-Earths is an exciting but challenging task because of the 10-10 contrast ratio between these planets and their host star at separations narrower than 100 mas. Large segmented aperture space telescopes enable the sensitivity needed to observe a large number of planets. Combined with coronagraphs with wavefront control, they present a...
Imaging exo-Earths is an exciting but challenging task because of the 10-10 contrast ratio between these planets and their host star at separations narrower than 100 mas. Large segmented aperture space telescopes enable the sensitivity needed to observe a large number of planets. Combined with coronagraphs with wavefront control, they present a...
Future large segmented space telescopes and their coronagraphic instruments are expected to provide the resolution and sensitivity to observe Earth-like planets with a 1010 contrast ratio at less than 100 mas from their host star. Advanced coronagraphs and wavefront control methods will enable the generation of high-contrast dark holes in the...
The SPHERE (Spectro-Polarimetric High-contrast Exoplanet Research) planet finder instrument for ESO's VLT telescope, scheduled for first light in 2011, aims to detect giant extra-solar planets in the vicinity of bright stars by the aid of an extreme-AO turbulence compensation system and to characterize the objects found through spectroscopic...
The combination on large ground-based telescopes of extreme adaptive optics (ExAO), coronagraphy and high-dispersion spectroscopy is starting to emerge as a powerful technique for the direct characterisation of giant exoplanets. High spectral resolution not only brings a major gain in terms of accessible spectral features, but it also enables...