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136 results on '"Coudé du Foresto, V."'

104. Cepheid Distances from Interferometry.

Author

Leibundgut, Bruno, Richichi, A., Delplancke, F., Paresce, F., Chelli, A., Kervella, P., Nardetto, N., Bersier, D., Mourard, D., Fouqué, P., and Coudé du Foresto, V.

Abstract

Long baseline interferometry is now able to resolve the pulsational changes of the angular diameters of a significant number of Cepheids in the solar neighborhood. This allows us to apply a new version of the Baade-Wesselink method to measure their distances, for which we do not need to estimate the star's temperature. Using this method and angular diameter measurements from the VLT Interferometer, we derived the distances to four nearby Cepheids. For three additional stars, we obtained average values of their angular diameters and we estimated their distances from previously published values of their linear sizes. Based on these new measurements and already existing data, we derived new calibrations of the Period-Luminosity and Period-Radius relations. Additionally, we obtained high precision surface brightness-color relations based solely on interferometric angular diameter measurements on Cepheids and BVRIJHK magnitudes. We finally discuss the prospects of the direct distance measurements of Cepheids. [ABSTRACT FROM AUTHOR]

Published
2008
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105. Limb Darkening: Getting Warmer.

Author

Leibundgut, Bruno, Richichi, A., Delplancke, F., Paresce, F., Chelli, A., Aufdenberg, J. P., Ludwig, H.-G., Kervella, P., Mérand, A., Ridgway, S. T., Coudé du Foresto, V., ten Brummelaar, T. A., Berger, D. H., Sturmann, J., and Turner, N. H.

Abstract

We present interferometric observations and model atmosphere analyses of three stars: the F-type subgiant Procyon, the A-type supergiant Deneb, and the B-type supergiant Rigel. We use VLTI/VINCI and Mark III observations of Procyon to test recent multiwavelength limb-darkening predictions from 3-D hydrodynamic atmosphere simulations with no free parameters for convection. We also investigate the effects of different 1-D atmospheric convection treatments on limb-darkening predictions. We show that the 3-D model predictions are confirmed and we find that 1-D models fail to reproduce Procyon's UV spectral energy distribution, a result consistent with models of granulation for Procyon's surface. We use observations employing the longest baselines of the CHARA Array together with the FLUOR beam combiner to determine precise angular diameters for the two early-type supergiants and test limb-darkening predictions from expanding atmosphere models of these tars' stellar winds. For Deneb, we derive angular diameters consistent with previous measurements, but which vary with position angle at the ≃3% level. Observations of the 2nd lobe of Deneb's visibility curve are more consistent with expanding atmosphere predictions than hydrostatic atmosphere predictions. For Rigel, we derive from the CHARA/FLUOR observations a limb-darkened angular diameter consistent with a recent VLTI/IONIC measurement and 8% larger than reported from the Intensity Interferometer. [ABSTRACT FROM AUTHOR]

Published
2008
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106. The Molecular Layer of GCIRS7.

Author

Rodríguez-Coira, G., Amorim, A., Bauböck, M., Benisty, M., Berger, J.-P., Clénet, Y., Coudé Du Foresto, V., de Zeeuw, T., Dexter, J., Duvert, G., Eckart, A., Eisenhauer, F., Ferreira, Miguel C., Gao, F., Garcia, Paulo J. V., Gendron, E., Genzel, R., Gillessen, S., Gordo, P., and Habibi, M.

Published
2020

108. FADE, an instrument to measure the atmospheric coherence time

Author

Tokovinin, A., Kellerer, A., Coudé Du Foresto, V., Tokovinin, A., Kellerer, A., and Coudé Du Foresto, V.

Abstract

Aims.After proposing a new method of deriving the atmospheric time constant from the speed of focus variations (Kellerer & Tokovinin 2007, A&A, 461, 775), we now implement it with the new instrument, FADE.

Published
2008
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109. Interferometric observations of the multiple stellar system δVelorum

Author

Kellerer, A., Petr-Gotzens, M. G., Kervella, P., Coudé du Foresto, V., Kellerer, A., Petr-Gotzens, M. G., Kervella, P., and Coudé du Foresto, V.

Abstract

Context.The nearby (~24 pc) triple stellar system δVelorum contains a close, eclipsing binary (Aa, Ab) discovered in 2000. Multiple systems provide an opportunity to determine the set of fundamental parameters (mass, luminosity, size, chemical composition) of coeval stars.

Published
2007
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110. Circumstellar material in the Vegainner system revealed by CHARA/FLUOR

Author

Absil, O., di Folco, E., Mérand, A., Augereau, J.-C., Coudé du Foresto, V., Aufdenberg, J. P., Kervella, P., Ridgway, S. T., Berger, D. H., ten Brummelaar, T. A., Sturmann, J., Sturmann, L., Turner, N. H., McAlister, H. A., Absil, O., di Folco, E., Mérand, A., Augereau, J.-C., Coudé du Foresto, V., Aufdenberg, J. P., Kervella, P., Ridgway, S. T., Berger, D. H., ten Brummelaar, T. A., Sturmann, J., Sturmann, L., Turner, N. H., and McAlister, H. A.

Abstract

Context.Only a handful of debris disks have been imaged up to now. Due to the need for high dynamic range and high angular resolution, very little is known about the inner planetary region, where small amounts of warm dust are expected to be found.

Published
2006
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111. Interferometric spectrophotometry of Pegasides: APISD the Antarctic Plateau Interferometer Science Demonstrator

Author

Coudé du Foresto, V., Swain, M., Vakili, F., Coudé du Foresto, V., Swain, M., and Vakili, F.

Abstract

We propose a science demonstration experiment for antarctic stellar interferometry, dedicated to the goal of obtaining the first low-resolution spectra in the thermal infrared of a few “hot Jupiter” type exoplanets. It would provide a unique platform to acquire operational experience, and build up an extensive database on the relevant site properties at Dome C, as a preparation for a more ambitious facility.

Published
2005
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112. The science of ARIEL (Atmospheric Remote-sensing Infrared Exoplanet Large-survey)

Author

MacEwen, Howard A., Fazio, Giovanni G., Lystrup, Makenzie, Batalha, Natalie, Siegler, Nicholas, Tong, Edward C., Tinetti, G., Drossart, P., Eccleston, P., Hartogh, P., Heske, A., Leconte, J., Micela, G., Ollivier, M., Pilbratt, G., Puig, L., Turrini, D., Vandenbussche, B., Wolkenberg, P., Pascale, E., Beaulieu, J.-P., Güdel, M., Min, M., Rataj, M., Ray, T., Ribas, I., Barstow, J., Bowles, N., Coustenis, A., Coudé du Foresto, V., Decin, L., Encrenaz, T., Forget, F., Friswell, M, Griffin, M., Lagage, P. O., Malaguti, P., Moneti, A., Morales, J. C., Pace, E., Rocchetto, M., Sarkar, S., Selsis, F., Taylor, W., Tennyson, J., Venot, O., Waldmann, I. P., Wright, G., Zingales, T., and Zapatero-Osorio, M. R.

Published
2016
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116. ALADDIN NULLING INSTRUMENT.

Author

Barillot, M., Coudé du Foresto, V., Surdej, J., Absil, O., Jamar, C., and di Folco, E.

Subjects
*SPACE interferometry, *FOCAL planes, *SPECTRAL sensitivity, *ASTRONOMICAL instruments, *OPTICAL measurements
Abstract

The ALADDIN project aims at detecting warm dust populations around nearby main sequence stars. In order to achieve the significantly improved sensitivity with respect to existing instruments, the architecture of the system is focused and optimised for the mission: ALADDIN implements the nulling interferometry technique at the focal plane of a 2-telescope interferometer mounted on a rotating structural beam. Concerning the beam combining nulling instrument, the ALADDIN design is inherited from a Definition Study of the VLTI/GENIE instrument. In this paper, we demonstrate how the ALADDIN instrument preliminary definition can be made simpler and more representative of a space instrument than GENIE thanks to both the outstanding atmospheric properties of Dome C and the dedicated architecture of the system. Finally, we discuss the compatibility of the instrument with the Antarctic environment and constraints, and underline the experimental and industrial know-how learnt from the MAII and PERSEE nulling breadboards in which our Team is also involved. [ABSTRACT FROM AUTHOR]

Published
2010
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117. EXOZODIACAL DISCS WITH ALADDIN: HOW FAINT CAN WE DETECT THEM?

Author

Absil, O., Coudé du Foresto, V., Barillot, M., Daudigeos, X., Defr ere, D., den Hartog, R., Di Folco, E., and Surdej, J.

Subjects
*INTERFEROMETERS, *ZODIACAL light, *MATHEMATICAL optimization, *ASTRONOMICAL observations, *ASTRONOMICAL instruments
Abstract

In this paper, we describe the expected performance of ALADDIN, a nulling interferometer project optimised for operation at Dome C. After reviewing the main atmospheric parameters pertaining to infrared interferometry on the high Antarctic plateau, we shortly describe the ALADDIN instrument and compute its estimated performance in terms of the smallest exozodiacal dust disc density that can be detected. Our estimations are based on a thorough end-to-end software simulator previously developed for the GENIE nulling interferometer project at VLTI. We then propose a possible mission scenario, where the southern target stars of future exo-Earth characterisation missions can be surveyed for the presence of bright exozodiacal discs (>50 zodi) within one winter-over at Concordia. [ABSTRACT FROM AUTHOR]

Published
2010
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118. MYKERINOS: PREPARING LONG BASELINE INTERFEROMETRY AT DOME C.

Author

Abe, L., Schmider, F.-X., Daban, J.-B., Petrov, R., Valat, B., Vakili, F., and Coudé du Foresto, V.

Subjects
INTERFEROMETRY, ASTRONOMICAL observatories, FAINT Object Camera, INTERFEROMETERS, LARGE astronomical telescopes, ASTRONOMICAL instruments
Abstract

Site studies have proved Dome C to be an excellent site for optical interferometry, maybe the only possible site on Earth for the deployement of a large post-VLTI interferometric facility, like KEOPS. Indeed, recent studies have shown the possiblity of interferometric observations of faint objects, high sensitivity and high precision observations, direct imaging and nulling interferometry. However the achievement of this ambitious project assumes the pavement of a roadmap, including different steps. The first one should be a demonstrator, called Mykerinos. Mykerinos is a diluted aperture interferometer composed of at least two light collecting units with a baseline between 40 to 100 m (or more) consisting of 50 cm diameter telescopes. The telescope design is directly derived from our Laboratory's experience in the ASTEP experiment. Mykerinos will be equipped with a dual field focal instrument which is a pre-requisite for its site testing, as well as for its science demonstration purposes. [ABSTRACT FROM AUTHOR]

Published
2010
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119. Current results of the PERSEE testbench: the cophasing control and the polychromatic null rate

Author

Lozi, J., Cassaing, F., Le Duigou, J.-M., Sorrente, B., Montri, J., Reess, J.-M., Lhome, E., Buey, T., Hénault, F., Marcotto, A., Girard, P., Barillot, M., Ollivier, M., and Coudé du Foresto, V.

Abstract

Stabilizing a nulling interferometer at a nanometric level is the key issue to obtain deep null depths. The PERSEE breadboard has been designed to study and optimize the operation of cophased nulling bench in the most realistic disturbing environment of a space mission. This presentation focuses on the current results of the PERSEE bench. In terms of metrology, we cophased at 0.33 nm rms for the piston and 60 mas rms for the tip/tilt. A Linear Quadratic Gaussian (LQG) control coupled with an unsupervised vibration identification allows us to maintain that level of correction, even with characteristic vibrations of nulling interferometry space missions. These performances, with an accurate design and alignment of the bench, currently lead to a polychromatic unpolarised null depth of 8.9 × 10-6stabilized at 2.7 × 10-7on the [1.65 - 2.45] m spectral band (37% bandwidth). With those significant results, we give the first more general lessons we have already learned from this experiment, both at system and component levels for a future space mission.

Published
2011
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120. Infrared interferometric observations of nearby exozodiacal disks: current status and perspectives

Author

Defrère, D., Absil, O., Di Folco, E., Coudé Du Foresto, V., Antoine Mérand, Augereau, J. -C, 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, and 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

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

International audience

121. Infrared Imaging

Author

Danchi, W., Lawson, P., Absil, O., Akeson, R., Bally, J., Barry, R., Beichman, C., Belu, A., Boyce, M., Breckinridge, J., Burrows, A., Chen, C., Cole, D., Crisp, D., Danner, R., Deroo, P., Coudé Du Foresto, V., Defrère, D., Ebbets, D., Falkowski, P., Gappinger, R., Haugabook, I., Hanot, C., Henning, T., Hinz, P., Hollis, J., Hunyadi, S., Hyland, D., Johnston, K., Kaltenegger, L., Kasting, J., Kenworthy, M., Ksendzov, A., Lane, B., Laughlin, G., Lay, O., Liseau, R., Lopez, B., Millan-Gabet, R., Martin, S., Mawet, D., Mennesson, B., John D Monnier, Murakami, N., Noecker, C., Nishikawa, J., Pesesen, M., Peters, R., Quillen, A., Ragland, S., Rinehart, S., Rottgering, H., Scharf, D., Serabyn, G., Tamura, M., Tehrani, M., Traub, W., Unwin, S., Wilner, D., Woilliez, J., Woolf, N., and Zhao, M.

122. Infrared Interferometric Gravity Darkening Observations of Vega with CHARA/FLUOR

Author

Aufdenberg, J., Antoine Mérand, Coudé Du Foresto, V., Absil, O., Di Folco, E., Kervella, P., Ridgway, S., Berger, D., Ten Brummelaar, T., Mcalister, H., Sturmann, J., Turner, N., 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, and 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

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

International audience

123. Hot Circumstellar Material around Vega

Author

Absil, O., Di Folco, E., Antoine Mérand, Coudé Du Foresto, V., Augereau, J., Aufdenberg, J., Kervella, A., Ridgway, S., Ten Brummelaar, T., Mcalister, H., 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, and 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

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

International audience

124. Cepheid distances from infrared long-baseline interferometry - I. VINCI/VLTI observations of seven Galactic Cepheids

Author

Mourard, D., Nardetto, N., Bersier, D., Kervella, P., Coudé Du Foresto, V., Foresto, V., Du Foresto, V., Laboratoire Gemini (LG), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, and Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Systematic error, 010308 nuclear & particles physics, Infrared, Cepheid variable, Astrophysics (astro-ph), FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, 01 natural sciences, Stars, Interferometry, Space and Planetary Science, Angular diameter, Error bar, 0103 physical sciences, 010303 astronomy & astrophysics
Abstract

We report the angular diameter measurements of seven classical Cepheids (X Sgr, eta Aql, W Sgr, zeta Gem, beta Dor, Y Oph and L Car) that we have obtained with the VINCI instrument, installed at ESO's VLT Interferometer (VLTI). We also present reprocessed archive data obtained with the FLUOR/IOTA instrument on zeta Gem, in order to improve the phase coverage of our observations. We obtain average limb darkened angular diameter values of LD(X Sgr) = 1.471 +/- 0.033 mas, LD(eta Aql) = 1.839 +/- 0.028 mas, LD(W Sgr) = 1.312 +/- 0.029 mas, LD(beta Dor) = 1.891 +/- 0.024 mas, LD(zeta Gem) =1.747 +/- 0.061 mas, LD(Y Oph) = 1.437 +/- 0.040 mas and LD(L Car) = 2.988 +/- 0.012 mas. For four of these stars (eta Aql, W Sgr, beta Dor, and L Car) we detect the pulsational variation of their angular diameter. This enables us to compute directly their distances, using a modified version of the Baade-Wesselink method: d(eta Aql) = 276 [+55 -38] pc, d(W Sgr) = 379 [+216 -130] pc, d(beta Dor) = 345 [+175 -80] pc, d(L Car) = 603 [+24 -19] pc. The stated error bars are statistical in nature. Applying a hybrid method, that makes use of the Gieren et al. (1998) Period-Radius relation to estimate the linear diameters, we obtain the following distances (statistical and systematic error bars are mentioned): d(X Sgr) = 324 +/- 7 +/- 17 pc, d(eta Aql) = 264 +/- 4 +/- 14 pc, d(W Sgr) = 386 +/- 9 +/- 21 pc, d(beta Dor) = 326 +/- 4 +/- 19 pc, d(zeta Gem) = 360 +/- 13 +/- 22 pc, d(Y Oph) = 648 +/- 17 +/- 47 pc and d(L Car) = 542 +/- 2 +/- 49 pc., 16 pages, 12 figures, accepted for publication in Astronomy & Astrophysics

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125. Interferometric Observations of Cepheids. p-factor and center to limb darkening measurements

Author

Antoine Mérand, Kervella, P., Coudé Du Foresto, V., Ten Brummelaar, T., Mcalister, H., 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, and 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

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

International audience

126. EChO: Exoplanet characterisation observatory

Author

Tinetti, G., Beaulieu, J. P., Henning, T., Meyer, M., Micela, G., Ribas, I., Stam, D., Swain, M., Krause, O., Ollivier, M., Pace, E., Swinyard, B., Aylward, A., van Boekel, R., Coradini, A., Encrenaz, T., Snellen, I., Zapatero-Osorio, M. R., Bouwman, J., Cho, J. Y-K., Coudé du Foresto, V., Guillot, T., Lopez-Morales, M., Mueller-Wodarg, I., Palle, E., Selsis, F., Sozzetti, A., Ade, P. A. R., Achilleos, N., Adriani, A., Agnor, C. B., Afonso, C., Allende Prieto, C., Bakos, G., Barber, R. J., Barlow, M., Batista, V., Bernath, P., Bézard, B., Bordé, P., Brown, L. R., Cassan, A., Cavarroc, C., Ciaravella, A., Cockell, C., Coustenis, A., Danielski, C., Decin, L., De Kok, R., Demangeon, O., Deroo, P., Doel, P., Drossart, P., Fletcher, L. N., Focardi, M., Forget, F., Fossey, S., Fouqué, P., Frith, J., Galand, M., Gaulme, P., González Hernández, J. I., Grasset, O., Grassi, D., Grenfell, J. L., Griffin, M. J., Griffith, C. A., Grözinger, U., Guedel, M., Guio, P., Hainaut, O., Hargreaves, R., Hauschildt, P. H., Heng, K., Heyrovsky, D., Hueso, R., Irwin, P., Kaltenegger, L., Kervella, P., Kipping, D., Koskinen, T. T., Kovács, G., La Barbera, A., Lammer, H., Lellouch, E., Leto, G., Lopez Valverde, M. A., Lopez-Puertas, M., Lovis, C., Maggio, A., Maillard, J. P., Maldonado Prado, J., Marquette, J. B., Martin-Torres, F. J., Maxted, P., Miller, S., Molinari, S., Montes, D., Moro-Martin, A., Moses, J. I., Mousis, O., Nguyen Tuong, N., Nelson, R., Orton, G. S., Pantin, E., Pascale, E., Pezzuto, S., Pinfield, D., Poretti, E., Prinja, R., Prisinzano, L., Rees, J. M., Reiners, A., Samuel, B., Sánchez-Lavega, A., Sanz Forcada, J., Sasselov, D., Savini, G., Sicardy, B., Smith, A., Stixrude, L., Strazzulla, G., Tennyson, J., Tessenyi, M., Vasisht, G., Vinatier, S., Viti, S., Waldmann, I., White, G. J., Widemann, T., Wordsworth, R., Yelle, R., Yung, Y., Yurchenko, S. N., Tinetti, G., Beaulieu, J. P., Henning, T., Meyer, M., Micela, G., Ribas, I., Stam, D., Swain, M., Krause, O., Ollivier, M., Pace, E., Swinyard, B., Aylward, A., van Boekel, R., Coradini, A., Encrenaz, T., Snellen, I., Zapatero-Osorio, M. R., Bouwman, J., Cho, J. Y-K., Coudé du Foresto, V., Guillot, T., Lopez-Morales, M., Mueller-Wodarg, I., Palle, E., Selsis, F., Sozzetti, A., Ade, P. A. R., Achilleos, N., Adriani, A., Agnor, C. B., Afonso, C., Allende Prieto, C., Bakos, G., Barber, R. J., Barlow, M., Batista, V., Bernath, P., Bézard, B., Bordé, P., Brown, L. R., Cassan, A., Cavarroc, C., Ciaravella, A., Cockell, C., Coustenis, A., Danielski, C., Decin, L., De Kok, R., Demangeon, O., Deroo, P., Doel, P., Drossart, P., Fletcher, L. N., Focardi, M., Forget, F., Fossey, S., Fouqué, P., Frith, J., Galand, M., Gaulme, P., González Hernández, J. I., Grasset, O., Grassi, D., Grenfell, J. L., Griffin, M. J., Griffith, C. A., Grözinger, U., Guedel, M., Guio, P., Hainaut, O., Hargreaves, R., Hauschildt, P. H., Heng, K., Heyrovsky, D., Hueso, R., Irwin, P., Kaltenegger, L., Kervella, P., Kipping, D., Koskinen, T. T., Kovács, G., La Barbera, A., Lammer, H., Lellouch, E., Leto, G., Lopez Valverde, M. A., Lopez-Puertas, M., Lovis, C., Maggio, A., Maillard, J. P., Maldonado Prado, J., Marquette, J. B., Martin-Torres, F. J., Maxted, P., Miller, S., Molinari, S., Montes, D., Moro-Martin, A., Moses, J. I., Mousis, O., Nguyen Tuong, N., Nelson, R., Orton, G. S., Pantin, E., Pascale, E., Pezzuto, S., Pinfield, D., Poretti, E., Prinja, R., Prisinzano, L., Rees, J. M., Reiners, A., Samuel, B., Sánchez-Lavega, A., Sanz Forcada, J., Sasselov, D., Savini, G., Sicardy, B., Smith, A., Stixrude, L., Strazzulla, G., Tennyson, J., Tessenyi, M., Vasisht, G., Vinatier, S., Viti, S., Waldmann, I., White, G. J., Widemann, T., Wordsworth, R., Yelle, R., Yung, Y., and Yurchenko, S. N.

Abstract

A dedicated mission to investigate exoplanetary atmospheres represents a major milestone in our quest to understand our place in the universe by placing our Solar System in context and by addressing the suitability of planets for the presence of life. EChO—the Exoplanet Characterisation Observatory—is a mission concept specifically geared for this purpose. EChO will provide simultaneous, multi-wavelength spectroscopic observations on a stable platform that will allow very long exposures. The use of passive cooling, few moving parts and well established technology gives a low-risk and potentially long-lived mission. EChO will build on observations by Hubble, Spitzer and ground-based telescopes, which discovered the first molecules and atoms in exoplanetary atmospheres. However, EChO's configuration and specifications are designed to study a number of systems in a consistent manner that will eliminate the ambiguities affecting prior observations. EChO will simultaneously observe a broad enough spectral region—from the visible to the mid-infrared—to constrain from one single spectrum the temperature structure of the atmosphere, the abundances of the major carbon and oxygen bearing species, the expected photochemically-produced species and magnetospheric signatures. The spectral range and resolution are tailored to separate bands belonging to up to 30 molecules and retrieve the composition and temperature structure of planetary atmospheres. The target list for EChO includes planets ranging from Jupiter-sized with equilibrium temperatures T eq up to 2,000 K, to those of a few Earth masses, with T eq ~ 300 K. The list will include planets with no Solar System analog, such as the recently discovered planets GJ1214b, whose density lies between that of terrestrial and gaseous planets, or the rocky-iron planet 55 Cnc e, with day-side temperature close to 3,000 K. As the number of detected exoplanets is

127. EChO: Exoplanet characterisation observatory

Author

Tinetti, G., Beaulieu, J. P., Henning, T., Meyer, M., Micela, G., Ribas, I., Stam, D., Swain, M., Krause, O., Ollivier, M., Pace, E., Swinyard, B., Aylward, A., van Boekel, R., Coradini, A., Encrenaz, T., Snellen, I., Zapatero-Osorio, M. R., Bouwman, J., Cho, J. Y-K., Coudé du Foresto, V., Guillot, T., Lopez-Morales, M., Mueller-Wodarg, I., Palle, E., Selsis, F., Sozzetti, A., Ade, P. A. R., Achilleos, N., Adriani, A., Agnor, C. B., Afonso, C., Allende Prieto, C., Bakos, G., Barber, R. J., Barlow, M., Batista, V., Bernath, P., Bézard, B., Bordé, P., Brown, L. R., Cassan, A., Cavarroc, C., Ciaravella, A., Cockell, C., Coustenis, A., Danielski, C., Decin, L., De Kok, R., Demangeon, O., Deroo, P., Doel, P., Drossart, P., Fletcher, L. N., Focardi, M., Forget, F., Fossey, S., Fouqué, P., Frith, J., Galand, M., Gaulme, P., González Hernández, J. I., Grasset, O., Grassi, D., Grenfell, J. L., Griffin, M. J., Griffith, C. A., Grözinger, U., Guedel, M., Guio, P., Hainaut, O., Hargreaves, R., Hauschildt, P. H., Heng, K., Heyrovsky, D., Hueso, R., Irwin, P., Kaltenegger, L., Kervella, P., Kipping, D., Koskinen, T. T., Kovács, G., La Barbera, A., Lammer, H., Lellouch, E., Leto, G., Lopez Valverde, M. A., Lopez-Puertas, M., Lovis, C., Maggio, A., Maillard, J. P., Maldonado Prado, J., Marquette, J. B., Martin-Torres, F. J., Maxted, P., Miller, S., Molinari, S., Montes, D., Moro-Martin, A., Moses, J. I., Mousis, O., Nguyen Tuong, N., Nelson, R., Orton, G. S., Pantin, E., Pascale, E., Pezzuto, S., Pinfield, D., Poretti, E., Prinja, R., Prisinzano, L., Rees, J. M., Reiners, A., Samuel, B., Sánchez-Lavega, A., Sanz Forcada, J., Sasselov, D., Savini, G., Sicardy, B., Smith, A., Stixrude, L., Strazzulla, G., Tennyson, J., Tessenyi, M., Vasisht, G., Vinatier, S., Viti, S., Waldmann, I., White, G. J., Widemann, T., Wordsworth, R., Yelle, R., Yung, Y., Yurchenko, S. N., Tinetti, G., Beaulieu, J. P., Henning, T., Meyer, M., Micela, G., Ribas, I., Stam, D., Swain, M., Krause, O., Ollivier, M., Pace, E., Swinyard, B., Aylward, A., van Boekel, R., Coradini, A., Encrenaz, T., Snellen, I., Zapatero-Osorio, M. R., Bouwman, J., Cho, J. Y-K., Coudé du Foresto, V., Guillot, T., Lopez-Morales, M., Mueller-Wodarg, I., Palle, E., Selsis, F., Sozzetti, A., Ade, P. A. R., Achilleos, N., Adriani, A., Agnor, C. B., Afonso, C., Allende Prieto, C., Bakos, G., Barber, R. J., Barlow, M., Batista, V., Bernath, P., Bézard, B., Bordé, P., Brown, L. R., Cassan, A., Cavarroc, C., Ciaravella, A., Cockell, C., Coustenis, A., Danielski, C., Decin, L., De Kok, R., Demangeon, O., Deroo, P., Doel, P., Drossart, P., Fletcher, L. N., Focardi, M., Forget, F., Fossey, S., Fouqué, P., Frith, J., Galand, M., Gaulme, P., González Hernández, J. I., Grasset, O., Grassi, D., Grenfell, J. L., Griffin, M. J., Griffith, C. A., Grözinger, U., Guedel, M., Guio, P., Hainaut, O., Hargreaves, R., Hauschildt, P. H., Heng, K., Heyrovsky, D., Hueso, R., Irwin, P., Kaltenegger, L., Kervella, P., Kipping, D., Koskinen, T. T., Kovács, G., La Barbera, A., Lammer, H., Lellouch, E., Leto, G., Lopez Valverde, M. A., Lopez-Puertas, M., Lovis, C., Maggio, A., Maillard, J. P., Maldonado Prado, J., Marquette, J. B., Martin-Torres, F. J., Maxted, P., Miller, S., Molinari, S., Montes, D., Moro-Martin, A., Moses, J. I., Mousis, O., Nguyen Tuong, N., Nelson, R., Orton, G. S., Pantin, E., Pascale, E., Pezzuto, S., Pinfield, D., Poretti, E., Prinja, R., Prisinzano, L., Rees, J. M., Reiners, A., Samuel, B., Sánchez-Lavega, A., Sanz Forcada, J., Sasselov, D., Savini, G., Sicardy, B., Smith, A., Stixrude, L., Strazzulla, G., Tennyson, J., Tessenyi, M., Vasisht, G., Vinatier, S., Viti, S., Waldmann, I., White, G. J., Widemann, T., Wordsworth, R., Yelle, R., Yung, Y., and Yurchenko, S. N.

Abstract

A dedicated mission to investigate exoplanetary atmospheres represents a major milestone in our quest to understand our place in the universe by placing our Solar System in context and by addressing the suitability of planets for the presence of life. EChO—the Exoplanet Characterisation Observatory—is a mission concept specifically geared for this purpose. EChO will provide simultaneous, multi-wavelength spectroscopic observations on a stable platform that will allow very long exposures. The use of passive cooling, few moving parts and well established technology gives a low-risk and potentially long-lived mission. EChO will build on observations by Hubble, Spitzer and ground-based telescopes, which discovered the first molecules and atoms in exoplanetary atmospheres. However, EChO's configuration and specifications are designed to study a number of systems in a consistent manner that will eliminate the ambiguities affecting prior observations. EChO will simultaneously observe a broad enough spectral region—from the visible to the mid-infrared—to constrain from one single spectrum the temperature structure of the atmosphere, the abundances of the major carbon and oxygen bearing species, the expected photochemically-produced species and magnetospheric signatures. The spectral range and resolution are tailored to separate bands belonging to up to 30 molecules and retrieve the composition and temperature structure of planetary atmospheres. The target list for EChO includes planets ranging from Jupiter-sized with equilibrium temperatures T eq up to 2,000 K, to those of a few Earth masses, with T eq ~ 300 K. The list will include planets with no Solar System analog, such as the recently discovered planets GJ1214b, whose density lies between that of terrestrial and gaseous planets, or the rocky-iron planet 55 Cnc e, with day-side temperature close to 3,000 K. As the number of detected exoplanets is

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128. The science of ARIEL (Atmospheric Remote-sensing Infrared Exoplanet Large-survey)

Author

MacEwen, Howard A., Fazio, Giovanni G., Lystrup, Makenzie, Batalha, Natalie, Siegler, Nicholas, Tong, Edward C., Tinetti, G., Drossart, P., Eccleston, P., Hartogh, P., Heske, A., Leconte, J., Micela, G., Ollivier, M., Pilbratt, G., Puig, L., Turrini, D., Vandenbussche, B., Wolkenberg, P., Pascale, Enzo, Beaulieu, J.-P., Güdel, M., Min, M., Rataj, M., Ray, T., Ribas, I., Barstow, J., Bowles, N., Coustenis, A., Coudé du Foresto, V., Decin, L., Encrenaz, T., Forget, F., Friswell, M, Griffin, M., Lagage, P. O., Malaguti, P., Moneti, A., Morales, J. C., Pace, E., Rocchetto, M., Sarkar, Subhajit, Selsis, F., Taylor, W., Tennyson, J., Venot, O., Waldmann, I. P., Wright, G., Zingales, T., Zapatero-Osorio, M. R., MacEwen, Howard A., Fazio, Giovanni G., Lystrup, Makenzie, Batalha, Natalie, Siegler, Nicholas, Tong, Edward C., Tinetti, G., Drossart, P., Eccleston, P., Hartogh, P., Heske, A., Leconte, J., Micela, G., Ollivier, M., Pilbratt, G., Puig, L., Turrini, D., Vandenbussche, B., Wolkenberg, P., Pascale, Enzo, Beaulieu, J.-P., Güdel, M., Min, M., Rataj, M., Ray, T., Ribas, I., Barstow, J., Bowles, N., Coustenis, A., Coudé du Foresto, V., Decin, L., Encrenaz, T., Forget, F., Friswell, M, Griffin, M., Lagage, P. O., Malaguti, P., Moneti, A., Morales, J. C., Pace, E., Rocchetto, M., Sarkar, Subhajit, Selsis, F., Taylor, W., Tennyson, J., Venot, O., Waldmann, I. P., Wright, G., Zingales, T., and Zapatero-Osorio, M. R.

Abstract

The Atmospheric Remote-Sensing Infrared Exoplanet Large-survey (ARIEL) is one of the three candidate missions selected by the European Space Agency (ESA) for its next medium-class science mission due for launch in 2026. The goal of the ARIEL mission is to investigate the atmospheres of several hundred planets orbiting distant stars in order to address the fundamental questions on how planetary systems form and evolve. During its four (with a potential extension to six) years mission ARIEL will observe 500+ exoplanets in the visible and the infrared with its meter-class telescope in L2. ARIEL targets will include gaseous and rocky planets down to the Earth-size around different types of stars. The main focus of the mission will be on hot and warm planets orbiting close to their star, as they represent a natural laboratory in which to study the chemistry and formation of exoplanets. The ARIEL mission concept has been developed by a consortium of more than 50 institutes from 12 countries, which include UK, France, Italy, Germany, the Netherlands, Poland, Spain, Belgium, Austria, Denmark, Ireland and Portugal. The analysis of the ARIEL spectra and photometric data in the 0.5-7.8 micron range will allow to extract the chemical fingerprints of gases and condensates in the planets’ atmospheres, including the elemental composition for the most favorable targets. It will also enable the study of thermal and scattering properties of the atmosphere as the planet orbit around the star. ARIEL will have an open data policy, enabling rapid access by the general community to the high-quality exoplanet spectra that the core survey will deliver.

129. Unraveling the Mystery of Exozodiacal Dust

Author

Ertel, S., Augereau, J.-C, Thébault, P., Absil, O., Bonsor, A., Defrère, D., Kral, Q., Le Bouquin, J.-B, Lebreton, J., Coudé du Foresto, V., Ertel, S., Augereau, J.-C, Thébault, P., Absil, O., Bonsor, A., Defrère, D., Kral, Q., Le Bouquin, J.-B, Lebreton, J., and Coudé du Foresto, V.

Abstract

Exozodiacal dust clouds are thought to be the extrasolar analogs of the Solar System's zodiacal dust. Studying these systems provides insights in the architecture of the innermost regions of planetary systems, including the Habitable Zone. Furthermore, the mere presence of the dust may result in major obstacles for direct imaging of earth-like planets. Our EXOZODI project aims to detect and study exozodiacal dust and to explain its origin. We are carrying out the first large, near-infrared interferometric survey in the northern (CHARA/FLUOR) and southern (VLTI/PIONIER) hemispheres. Preliminary results suggest a detection rate of up to 30% around A to K type stars and interesting trends with spectral type and age. We focus here on presenting the observational work carried out by our team

130. Astrometry and K -band spectroscopy of HR 8799 e

Author

Lacour, S., Nowak, M., Wang, J., Pfuhl, O., Eisenhauer, F., Abuter, R., Amorim, A., Anugu, N., Benisty, M., Berger, J. P., Beust, H., Blind, N., Bonnefoy, M., Bonnet, H., Bourget, P., Brandner, W., Buron, A., Collin, C., Charnay, B., Chapron, F., Clénet, Y., Coudé du Foresto, V., de Zeeuw, P. T., Deen, C., Dembet, R., Dexter, J., Duvert, G., Eckart, A., Förster Schreiber, N. M., Fédou, P., Garcia, P., Garcia Lopez, R., Gao, F., Gendron, E., Genzel, R., Gillessen, S., Gordo, P., Greenbaum, A., Habibi, M., Haubois, X., Haußmann, F., Henning, Th., Hippler, S., Horrobin, M., Hubert, Z., Jimenez Rosales, A., Jocou, L., Kendrew, S., Kervella, P., Kolb, J., Lagrange, A.-M., Lapeyrère, V., Le Bouquin, J.-B., Léna, P., Lippa, M., Lenzen, R., Maire, A.-L., Mollière, P., Ott, T., Paumard, T., Perraut, K., Perrin, G., Pueyo, L., Rabien, S., Ramírez, A., Rau, C., Rodríguez-Coira, G., Rousset, G., Sanchez-Bermudez, J., Scheithauer, S., Schuhler, N., Straub, O., Straubmeier, C., Sturm, E., Tacconi, L. J., Vincent, F., van Dishoeck, E. F., von Fellenberg, S., Wank, I., Waisberg, I., Widmann, F., Wieprecht, E., Wiest, M., Wiezorrek, E., Woillez, J., Yazici, S., Ziegler, D., and Zins, G.

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131. The GRAVITY young stellar object survey

Author

Caratti O Garatti, A., Fedriani, R., Garcia Lopez, R., Koutoulaki, M., Perraut, K., Linz, H., Brandner, W., Garcia, P., Klarmann, L., Henning, T., Labadie, L., Sanchez-Bermudez, J., Lazareff, B., Van Dishoeck, E., Caselli, P., de Zeeuw, P., Bik, A., Benisty, M., Dougados, C., Ray, T., Amorim, A., Berger, J.-P., Clénet, Y., Coudé Du Foresto, V., Duvert, G., Eckart, A., Eisenhauer, F., Gao, F., Gendron, E., Genzel, R., Gillessen, S., Gordo, P., Jocou, L., Horrobin, M., Kervella, P., Lacour, S., Le Bouquin, J.-B., Léna, P., Grellmann, R., Ott, T., Paumard, T., Perrin, G., Rousset, G., Scheithauer, S., Shangguan, J., Stadler, J., Straub, O., Straubmeier, C., Sturm, E., Thi, W., Vincent, F., Widmann, F., 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, and 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)

Subjects
[SDU]Sciences of the Universe [physics], ComputingMilieux_MISCELLANEOUS
Abstract

International audience

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134. Interferometric radius and limb darkening of the asteroseismic red giant ηSerpentis with the CHARA Array

Author

Mérand, A., Kervella, P., Barban, C., Josselin, E., Brummelaar, T. A. ten, McAlister, H. A., Coudé du Foresto, V., Ridgway, S. T., Turner, N., Sturmann, J., Sturmann, L., Goldfinger, P. J., and Farrington, C.

Abstract

Context. The radius of a star is a very important constraint to evolutionary models, particularly when combined with asteroseismology. Diameters can now be measured interferometrically with great precision (better than 1%), but the center-to-limb darkening (CLD) remains a potential source of bias. Measuring this bias is possible by completely resolving the star using long-baseline interferometry, and has only been achieved for a handful of stars.Aims. The red giant ηSer (K0III-IV) is a particularly interesting target, as asteroseismic oscillations have recently been detected in this star by spectroscopy. We aim to measure its radius with high accuracy, debiased from limb darkening, in order to bring new constraints to its models.Methods. We obtained interferometric observations of ηSer in the near-infrared using the CHARA/FLUOR instrument, in particular in the so-called second lobe of visibility in order to constrain the CLD and debias our diameter estimation.Results. The limb darkened angular diameter of ηSer is 2.944 ±0.010 mas (using spherical photosphere models PHOENIX and MARCS for the limb darkening), that converts into a radius of 5.897 ±0.028 $R_\odot$with the Hipparcosparallax. Thanks to a precise visibility measurement in the second lobe of the visibility function of ηSer and a one-parameter limb-darkened visibility profile, we were able to show that the photosphere models have the best agreement possible. Conclusions. Our limb darkening measurement of ηSer is in agreement with existing atmosphere models of this star, with a slightly better agreement for models using spherical geometry. This is a strong indication that interferometric angular diameter measurements for red giants, corrected for the CLD using models, are unbiased at a very small level (a fraction of 1%). In particular, this strengthens our confidence in the existing catalogues of calibrator stars for interferometry that are based on giant stars similar to ηSer. The high accuracy of our measurement brings a new and strong constraint for the asteroseismic modeling of this star.

Published
2010

135. The radius and effective temperature of the binary Ap star βCrB from CHARA/FLUOR and VLT/NACO observations*

Author

Bruntt, H., Kervella, P., Mérand, A., Brandão, I. M., Bedding, T. R., ten Brummelaar, T. A., Coudé du Foresto, V., Cunha, M. S., Farrington, C., Goldfinger, P. J., Kiss, L. L., McAlister, H. A., Ridgway, S. T., Sturmann, J., Sturmann, L., Turner, N., and Tuthill, P. G.

Abstract

Context. The prospects for using the asteroseismology of rapidly oscillating Ap (roAp) stars are hampered by the large uncertainty in fundamental stellar parameters. Results in the literature for the effective temperature (Teff) often span a range of 1000 K.Aims. Our goal is to reduce systematic errors and improve the Teffcalibration of Ap stars based on new interferometric measurements.Methods. We obtained long-baseline interferometric observations of βCrB using the CHARA/FLUOR instrument. To disentangle the flux contributions of the two components of this binary star, we obtained VLT/NACO adaptive optics images.Results. We determined limb-darkened angular diameters of 0.699±0.017 mas for βCrB A (from interferometry) and 0.415±0.017 mas for βCrB B (from surface brightness-colour relations), corresponding to radii of 2.63±0.09 ${R}_\odot$(3.4% uncertainty) and 1.56±0.07 ${R}_\odot$(4.5%). The combined bolometric flux of the A+B components was determined from satellite UV data, spectrophotometry in the visible, and broadband data in the infrared. The flux from the B component constitutes $16\pm4$% of the total flux and was determined by fitting an ATLAS9 model atmosphere to the broad-band NACO Jand Kmagnitudes. By combining the flux of the A component with its measured angular diameter, we determined the effective temperature Teff(A) = 7980±180 K ($2.3{\%}$).Conclusions. Our new interferometric and imaging data enable nearly model-independent determination of the effective temperature of βCrB A. Including our recent study of αCir, we now have direct Teffmeasurements of two of the brightest roAp stars, providing a strong benchmark for improved calibration of the Teffscale for Ap stars. This will support the use of potentially strong constraints imposed by asteroseismic studies of roAp stars.

Published
2010

136. Test of the Einstein Equivalence Principle near the Galactic Center Supermassive Black Hole.

Author

Amorim A, Bauböck M, Berger JP, Brandner W, Clénet Y, Coudé du Foresto V, de Zeeuw PT, Dexter J, Duvert G, Ebert M, Eckart A, Eisenhauer F, Förster Schreiber NM, Garcia P, Gao F, Gendron E, Genzel R, Gillessen S, Habibi M, Haubois X, Henning T, Hippler S, Horrobin M, Hubert Z, Jiménez Rosales A, Jocou L, Kervella P, Lacour S, Lapeyrère V, Le Bouquin JB, Léna P, Ott T, Paumard T, Perraut K, Perrin G, Pfuhl O, Rabien S, Rodríguez-Coira G, Rousset G, Scheithauer S, Sternberg A, Straub O, Straubmeier C, Sturm E, Tacconi LJ, Vincent F, von Fellenberg S, Waisberg I, Widmann F, Wieprecht E, Wiezorrek E, and Yazici S

Abstract

During its orbit around the four million solar mass black hole Sagittarius A* the star S2 experiences significant changes in gravitational potential. We use this change of potential to test one part of the Einstein equivalence principle: the local position invariance (LPI). We study the dependency of different atomic transitions on the gravitational potential to give an upper limit on violations of the LPI. This is done by separately measuring the redshift from hydrogen and helium absorption lines in the stellar spectrum during its closest approach to the black hole. For this measurement we use radial velocity data from 2015 to 2018 and combine it with the gravitational potential at the position of S2, which is calculated from the precisely known orbit of S2 around the black hole. This results in a limit on a violation of the LPI of |β_{He}-β_{H}|=(2.4±5.1)×10^{-2}. The variation in potential that we probe with this measurement is six magnitudes larger than possible for measurements on Earth, and a factor of 10 larger than in experiments using white dwarfs. We are therefore testing the LPI in a regime where it has not been tested before.

Published
2019
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