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7 results on '"Hanot, Charles"'

1. Companion search around beta Pictoris with the newly commissioned L'-band vector vortex coronagraph on VLT/NACO

Author

Mawet, Dimitri, Absil, Olivier, Milli, Julien, Baudoz, Pierre, Boccaletti, Anthony, Chauvin, Gaël, Delacroix, Christian, Girard, J. H. V., Lagrange, Anne-Marie, O'Neal, Jared, Bourget, P., Forsberg, Pontus, Gonté, Frédéric, Habraken, Serge, Hanot, Charles, Karlsson, Mikael, Kasper, Markus E., Lizon, Jean-Louis, Muzic, Koraljka, Olivier, Richard, Peña, Eduardo, Slusarenko, Nicolas, Tacconi-Garman, Lowell E., Surdej, Jean, Matthews, Brenda C., Graham, James R., Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Haute résolution angulaire en astrophysique, Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), and Henry, Florence

Subjects
[PHYS.ASTR] Physics [physics]/Astrophysics [astro-ph], [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract

International audience

Published
2013

2. Extra-solar planet imaging: ground vs space based coronagraphs

Author

Hanot, Charles, Absil, Olivier, Boccaletti, Anthony, Vérinaud, Christophe, Surdej, Jean, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Pôle Astronomie du LESIA, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, and Henry, Florence

Subjects
[PHYS.ASTR] Physics [physics]/Astrophysics [astro-ph], [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract

International audience

Published
2010

3. Infrared Imaging

Author

Danchi, William, Lawson, Peter, Absil, Olivier, Hanot, Charles, Mawet, Dimitri, Lawson, P. R., Traub, W. A., and Unwin, S. C.

Subjects
Astrophysics::Instrumentation and Methods for Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract

A mid‐infrared mission would enable the detection of biosignatures of Earth‐like exoplanets around more than 150 nearby stars. The mid‐infrared spectral region is attractive for characterizing exoplanets because contrast with the parent star brightness is more favorable than in the visible (10 million vs. 10 billion), and because mid‐infrared light probes deep into a planet’s troposphere. Furthermore, the mid‐infrared offers access to several strong molecular features that are key signs of life, and also provides a measure of the effective temperature and size of a planet. Taken together, an infrared mission plus a visible one would provide a nearly full picture of a planet, including signs of life; with a measure of mass from an astrometric mission, we would have a virtually complete picture. A small infrared mission would have several telescopes that are rigidly connected, with a science return from the detection and characterization of super‐Earth sized to larger planets near the HZ, plus a direct measure of the exozodi brightness in the HZ. In a large infrared mission, with formation‐flying telescopes, planets from an Earth‐twin and upwards in mass could be detected and characterized, as well as the exozodi. If proceeded by an astrometric mission, the detection phase could be skipped and the mission devoted to characterization, as in the visible case; lacking an astrometric mission, an infrared one could proceed alone, as was discussed for a visible coronograph, and with similar caveats. The technology needed for a large formation‐flying mission is similar to that for a small connected‐element one (e.g., cryogenics and detectors), with the addition of formation-flying technology. The technology is now in hand to implement a probe‐scale mission; starlight suppression has even been demonstrated to meet the requirements of a flagship mission. However, additional development of formation‐flying technology is needed, particularly in‐space testing of sensors and guidance, navigation, and control algorithms.

Published
2009

7. Fresnel rhombs as achromatic phase shifters for infrared nulling interferometry.

Author

Mawet D, Hanot C, Lenaers C, Riaud P, Defrère D, Vandormael D, Loicq J, Fleury K, Plesseria JY, Surdej J, and Habraken S

Abstract

We propose a new family of achromatic phase shifters for infrared nulling interferometry. These key optical components can be seen as optimized Fresnel rhombs, using the total internal reflection phenomenon, modulated or not. The total internal reflection indeed comes with a phase shift between the polarization components of the incident light. We propose a solution to implement this vectorial phase shift between interferometer arms to provide the destructive interference process needed to disentangle highly contrasted objects from one another. We also show that, modulating the index transition at the total internal reflection interface allows compensating for the intrinsic material dispersion in order to make the subsequent phase shift achromatic over especially broad bands. The modulation can be induced by a thin film of a well-chosen material or a subwavelength grating whose structural parameters are thoroughly optimized. We present results from theoretical simulations together with preliminary fabrication outcomes and measurements for a prototype in Zinc Selenide.

Published
2007
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