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27 results on '"Bonneau P"'

1. VEGA: Visible spEctroGraph and polArimeter for the CHARA array: principle and performance

Author

Mourard, D., Clausse, J. M., Marcotto, A., Perraut, K., Tallon-Bosc, I., Bério, Ph., Blazit, A., Bonneau, D., Bosio, S., Bresson, Y., Chesneau, O., Delaa, O., Hénault, F., Hughes, Y., Lagarde, S., Merlin, G., Roussel, A., Spang, A., Stee, Ph., Tallon, M., Antonelli, P., Foy, R., Kervella, P., Petrov, R., Thiebaut, E., Vakili, F., McAlister, H., ten Brummelaar, T., Sturmann, J., Sturmann, L., Turner, N., Farrington, C., Goldfinger, P. J., Mourard, D., Clausse, J. M., Marcotto, A., Perraut, K., Tallon-Bosc, I., Bério, Ph., Blazit, A., Bonneau, D., Bosio, S., Bresson, Y., Chesneau, O., Delaa, O., Hénault, F., Hughes, Y., Lagarde, S., Merlin, G., Roussel, A., Spang, A., Stee, Ph., Tallon, M., Antonelli, P., Foy, R., Kervella, P., Petrov, R., Thiebaut, E., Vakili, F., McAlister, H., ten Brummelaar, T., Sturmann, J., Sturmann, L., Turner, N., Farrington, C., and Goldfinger, P. J.

Abstract

Context. Among optical stellar interferometers, the CHARA Array located at Mt Wilson in California offers the potential of very long baselines (up to 330 m) and the prospect of coupling multiple beam combiners. This paper presents the principle and the measured performance of VEGA, Visible spEctroGraph and polArimeter installed in September 2007 at the coherent focus of the array.

Published
2009
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2. Transiting exoplanets from the CoRoT space mission *

Author

Léger, A., Rouan, D., Schneider, J., Barge, P., Fridlund, M., Samuel, B., Ollivier, M., Guenther, E., Deleuil, M., Deeg, H. J., Auvergne, M., Alonso, R., Aigrain, S., Alapini, A., Almenara, J. M., Baglin, A., Barbieri, M., Bruntt, H., Bordé, P., Bouchy, F., Cabrera, J., Catala, C., Carone, L., Carpano, S., Csizmadia, Sz., Dvorak, R., Erikson, A., Ferraz-Mello, S., Foing, B., Fressin, F., Gandolfi, D., Gillon, M., Gondoin, Ph., Grasset, O., Guillot, T., Hatzes, A., Hébrard, G., Jorda, L., Lammer, H., Llebaria, A., Loeillet, B., Mayor, M., Mazeh, T., Moutou, C., Pätzold, M., Pont, F., Queloz, D., Rauer, H., Renner, S., Samadi, R., Shporer, A., Sotin, Ch., Tingley, B., Wuchterl, G., Adda, M., Agogu, P., Appourchaux, T., Ballans, H., Baron, P., Beaufort, T., Bellenger, R., Berlin, R., Bernardi, P., Blouin, D., Baudin, F., Bodin, P., Boisnard, L., Boit, L., Bonneau, F., Borzeix, S., Briet, R., Buey, J.-T., Butler, B., Cailleau, D., Cautain, R., Chabaud, P.-Y., Chaintreuil, S., Chiavassa, F., Costes, V., Cuna Parrho, V., De Oliveira Fialho, F., Decaudin, M., Defise, J.-M., Djalal, S., Epstein, G., Exil, G.-E., Fauré, C., Fenouillet, T., Gaboriaud, A., Gallic, A., Gamet, P., Gavalda, P., Grolleau, E., Gruneisen, R., Gueguen, L., Guis, V., Guivarc'h, V., Guterman, P., Hallouard, D., Hasiba, J., Heuripeau, F., Huntzinger, G., Hustaix, H., Imad, C., Imbert, C., Johlander, B., Jouret, M., Journoud, P., Karioty, F., Kerjean, L., Lafaille, V., Lafond, L., Lam-Trong, T., Landiech, P., Lapeyrere, V., Larqué, T., Laudet, P., Lautier, N., Lecann, H., Lefevre, L., Leruyet, B., Levacher, P., Magnan, A., Mazy, E., Mertens, F., Mesnager, J.-M., Meunier, J.-C., Michel, J.-P., Monjoin, W., Naudet, D., Nguyen-Kim, K., Orcesi, J.-L., Ottacher, H., Perez, R., Peter, G., Plasson, P., Plesseria, J.-Y., Pontet, B., Pradines, A., Quentin, C., Reynaud, J.-L., Rolland, G., Rollenhagen, F., Romagnan, R., Russ, N., Schmidt, R., Schwartz, N., Sebbag, I., Sedes, G., Smit, H., Steller, M. B., Sunter, W., Surace, C., Tello, M., Tiphène, D., Toulouse, P., Ulmer, B., Vandermarcq, O., Vergnault, E., Vuillemin, A., Zanatta, P., Léger, A., Rouan, D., Schneider, J., Barge, P., Fridlund, M., Samuel, B., Ollivier, M., Guenther, E., Deleuil, M., Deeg, H. J., Auvergne, M., Alonso, R., Aigrain, S., Alapini, A., Almenara, J. M., Baglin, A., Barbieri, M., Bruntt, H., Bordé, P., Bouchy, F., Cabrera, J., Catala, C., Carone, L., Carpano, S., Csizmadia, Sz., Dvorak, R., Erikson, A., Ferraz-Mello, S., Foing, B., Fressin, F., Gandolfi, D., Gillon, M., Gondoin, Ph., Grasset, O., Guillot, T., Hatzes, A., Hébrard, G., Jorda, L., Lammer, H., Llebaria, A., Loeillet, B., Mayor, M., Mazeh, T., Moutou, C., Pätzold, M., Pont, F., Queloz, D., Rauer, H., Renner, S., Samadi, R., Shporer, A., Sotin, Ch., Tingley, B., Wuchterl, G., Adda, M., Agogu, P., Appourchaux, T., Ballans, H., Baron, P., Beaufort, T., Bellenger, R., Berlin, R., Bernardi, P., Blouin, D., Baudin, F., Bodin, P., Boisnard, L., Boit, L., Bonneau, F., Borzeix, S., Briet, R., Buey, J.-T., Butler, B., Cailleau, D., Cautain, R., Chabaud, P.-Y., Chaintreuil, S., Chiavassa, F., Costes, V., Cuna Parrho, V., De Oliveira Fialho, F., Decaudin, M., Defise, J.-M., Djalal, S., Epstein, G., Exil, G.-E., Fauré, C., Fenouillet, T., Gaboriaud, A., Gallic, A., Gamet, P., Gavalda, P., Grolleau, E., Gruneisen, R., Gueguen, L., Guis, V., Guivarc'h, V., Guterman, P., Hallouard, D., Hasiba, J., Heuripeau, F., Huntzinger, G., Hustaix, H., Imad, C., Imbert, C., Johlander, B., Jouret, M., Journoud, P., Karioty, F., Kerjean, L., Lafaille, V., Lafond, L., Lam-Trong, T., Landiech, P., Lapeyrere, V., Larqué, T., Laudet, P., Lautier, N., Lecann, H., Lefevre, L., Leruyet, B., Levacher, P., Magnan, A., Mazy, E., Mertens, F., Mesnager, J.-M., Meunier, J.-C., Michel, J.-P., Monjoin, W., Naudet, D., Nguyen-Kim, K., Orcesi, J.-L., Ottacher, H., Perez, R., Peter, G., Plasson, P., Plesseria, J.-Y., Pontet, B., Pradines, A., Quentin, C., Reynaud, J.-L., Rolland, G., Rollenhagen, F., Romagnan, R., Russ, N., Schmidt, R., Schwartz, N., Sebbag, I., Sedes, G., Smit, H., Steller, M. B., Sunter, W., Surace, C., Tello, M., Tiphène, D., Toulouse, P., Ulmer, B., Vandermarcq, O., Vergnault, E., Vuillemin, A., and Zanatta, P.

Abstract

Aims. We report the discovery of very shallow ($\Delta F/F \approx 3.4\times 10^{-4}$), periodic dips in the light curve of an active $V = 11.7$G9V star observed by the CoRoT  satellite, which we interpret as caused by a transiting companion. We describe the 3-colour CoRoT data and complementary ground-based observations that support the planetary nature of the companion.

Published
2009
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3. The CoRoT satellite in flight: description and performance*

Author

Auvergne, M., Bodin, P., Boisnard, L., Buey, J.-T., Chaintreuil, S., Epstein, G., Jouret, M., Lam-Trong, T., Levacher, P., Magnan, A., Perez, R., Plasson, P., Plesseria, J., Peter, G., Steller, M., Tiphène, D., Baglin, A., Agogué, P., Appourchaux, T., Barbet, D., Beaufort, T., Bellenger, R., Berlin, R., Bernardi, P., Blouin, D., Boumier, P., Bonneau, F., Briet, R., Butler, B., Cautain, R., Chiavassa, F., Costes, V., Cuvilho, J., Cunha-Parro, V., De Oliveira Fialho, F., Decaudin, M., Defise, J.-M., Djalal, S., Docclo, A., Drummond, R., Dupuis, O., Exil, G., Fauré, C., Gaboriaud, A., Gamet, P., Gavalda, P., Grolleau, E., Gueguen, L., Guivarc'h, V., Guterman, P., Hasiba, J., Huntzinger, G., Hustaix, H., Imbert, C., Jeanville, G., Johlander, B., Jorda, L., Journoud, P., Karioty, F., Kerjean, L., Lafond, L., Lapeyrere, V., Landiech, P., Larqué, T., Laudet, P., Le Merrer, J., Leporati, L., Leruyet, B., Levieuge, B., Llebaria, A., Martin, L., Mazy, E., Mesnager, J.-M., Michel, J.-P., Moalic, J.-P., Monjoin, W., Naudet, D., Neukirchner, S., Nguyen-Kim, K., Ollivier, M., Orcesi, J.-L., Ottacher, H., Oulali, A., Parisot, J., Perruchot, S., Piacentino, A., Pinheiro da Silva, L., Platzer, J., Pontet, B., Pradines, A., Quentin, C., Rohbeck, U., Rolland, G., Rollenhagen, F., Romagnan, R., Russ, N., Samadi, R., Schmidt, R., Schwartz, N., Sebbag, I., Smit, H., Sunter, W., Tello, M., Toulouse, P., Ulmer, B., Vandermarcq, O., Vergnault, E., Wallner, R., Waultier, G., Zanatta, P., Auvergne, M., Bodin, P., Boisnard, L., Buey, J.-T., Chaintreuil, S., Epstein, G., Jouret, M., Lam-Trong, T., Levacher, P., Magnan, A., Perez, R., Plasson, P., Plesseria, J., Peter, G., Steller, M., Tiphène, D., Baglin, A., Agogué, P., Appourchaux, T., Barbet, D., Beaufort, T., Bellenger, R., Berlin, R., Bernardi, P., Blouin, D., Boumier, P., Bonneau, F., Briet, R., Butler, B., Cautain, R., Chiavassa, F., Costes, V., Cuvilho, J., Cunha-Parro, V., De Oliveira Fialho, F., Decaudin, M., Defise, J.-M., Djalal, S., Docclo, A., Drummond, R., Dupuis, O., Exil, G., Fauré, C., Gaboriaud, A., Gamet, P., Gavalda, P., Grolleau, E., Gueguen, L., Guivarc'h, V., Guterman, P., Hasiba, J., Huntzinger, G., Hustaix, H., Imbert, C., Jeanville, G., Johlander, B., Jorda, L., Journoud, P., Karioty, F., Kerjean, L., Lafond, L., Lapeyrere, V., Landiech, P., Larqué, T., Laudet, P., Le Merrer, J., Leporati, L., Leruyet, B., Levieuge, B., Llebaria, A., Martin, L., Mazy, E., Mesnager, J.-M., Michel, J.-P., Moalic, J.-P., Monjoin, W., Naudet, D., Neukirchner, S., Nguyen-Kim, K., Ollivier, M., Orcesi, J.-L., Ottacher, H., Oulali, A., Parisot, J., Perruchot, S., Piacentino, A., Pinheiro da Silva, L., Platzer, J., Pontet, B., Pradines, A., Quentin, C., Rohbeck, U., Rolland, G., Rollenhagen, F., Romagnan, R., Russ, N., Samadi, R., Schmidt, R., Schwartz, N., Sebbag, I., Smit, H., Sunter, W., Tello, M., Toulouse, P., Ulmer, B., Vandermarcq, O., Vergnault, E., Wallner, R., Waultier, G., and Zanatta, P.

Abstract

Context. CoRoT is a space telescope dedicated to stellar seismology and the search for extrasolar planets. The mission is led by the CNES in association with French laboratories and has a large international participation. The European Space Agency (ESA), Austria, Belgium, and Germany contribute to the payload, and Spain and Brazil contribute to the ground segment. Development of the spacecraft, which is based on a PROTEUS low earth orbit (LEO) recurrent platform, commenced in October 2000, and the satellite was launched on December 27, 2006.

Published
2009
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4. The circumbinary dusty disk around the hydrogen-deficient binary star $\mathsf{\upsilon}$Sagittarii ***

Author

Netolický, M., Bonneau, D., Chesneau, O., Harmanec, P., Koubský, P., Mourard, D., Stee, P., Netolický, M., Bonneau, D., Chesneau, O., Harmanec, P., Koubský, P., Mourard, D., and Stee, P.

Abstract

Aims. The aim of this paper is to determine the properties of the dusty environment of the hydrogen-deficient binary system υSgr, whose binary properties and other characteristics are poorly known.

Published
2009
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5. δCentauri: a new binary Be star detected by VLTI/AMBER spectro-interferometry*

Author

Meilland, A., Millour, F., Stee, Ph., Spang, A., Petrov, R., Bonneau, D., Perraut, K., Massi, F., Meilland, A., Millour, F., Stee, Ph., Spang, A., Petrov, R., Bonneau, D., Perraut, K., and Massi, F.

Abstract

Aims. We study the Be star δCen circumstellar disk using long-baseline interferometry which is the only observing technique capable of resolving spatially and spectroscopically objects smaller than 5 mas in the Hand Kband.

Published
2008
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6. First results from a laboratory hypertelescope using single-mode fibers

Author

Patru, F., Mourard, D., Clausse, J.-M., Delage, L., Reynaud, F., Dubreuil, M., Bonneau, D., Bosio, S., Bresson, Y., Hugues, Y., Lardière, O., Roussel, A., Patru, F., Mourard, D., Clausse, J.-M., Delage, L., Reynaud, F., Dubreuil, M., Bonneau, D., Bosio, S., Bresson, Y., Hugues, Y., Lardière, O., and Roussel, A.

Abstract

Context.In the future, giant optical interferometric arrays will be developed with kilometric baselines and a large number of telescopes. Such arrays could have direct imaging capabilities if optimized beam combiners are used.

Published
2008
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7. Direct constraint on the distance of γ2Velorum from AMBER/VLTI observations*

Author

Millour, F., Petrov, R. G., Chesneau, O., Bonneau, D., Dessart, L., Bechet, C., Tallon-Bosc, I., Tallon, M., Thiébaut, E., Vakili, F., Malbet, F., Mourard, D., Antonelli, P., Beckmann, U., Bresson, Y., Chelli, A., Dugué, M., Duvert, G., Gennari, S., Glück, L., Kern, P., Lagarde, S., Le Coarer, E., Lisi, F., Perraut, K., Puget, P., Rantakyrö, F., Robbe-Dubois, S., Roussel, A., Tatulli, E., Weigelt, G., Zins, G., Accardo, M., Acke, B., Agabi, K., Altariba, E., Arezki, B., Aristidi, E., Baffa, C., Behrend, J., Blöcker, T., Bonhomme, S., Busoni, S., Cassaing, F., Clausse, J.-M., Colin, J., Connot, C., Delboulbé, A., Domiciano de Souza, A., Driebe, T., Feautrier, P., Ferruzzi, D., Forveille, T., Fossat, E., Foy, R., Fraix-Burnet, D., Gallardo, A., Giani, E., Gil, C., Glentzlin, A., Heiden, M., Heininger, M., Hernandez Utrera, O., Hofmann, K.-H., Kamm, D., Kiekebusch, M., Kraus, S., Le Contel, D., Le Contel, J.-M., Lesourd, T., Lopez, B., Lopez, M., Magnard, Y., Marconi, A., Mars, G., Martinot-Lagarde, G., Mathias, P., Mège, P., Monin, J.-L., Mouillet, D., Nussbaum, E., Ohnaka, K., Pacheco, J., Perrier, C., Rabbia, Y., Rebattu, S., Reynaud, F., Richichi, A., Robini, A., Sacchettini, M., Schertl, D., Schöller, M., Solscheid, W., Spang, A., Stee, P., Stefanini, P., Tasso, D., Testi, L., von der Lühe, O., Valtier, J.-C., Vannier, M., Ventura, N., Millour, F., Petrov, R. G., Chesneau, O., Bonneau, D., Dessart, L., Bechet, C., Tallon-Bosc, I., Tallon, M., Thiébaut, E., Vakili, F., Malbet, F., Mourard, D., Antonelli, P., Beckmann, U., Bresson, Y., Chelli, A., Dugué, M., Duvert, G., Gennari, S., Glück, L., Kern, P., Lagarde, S., Le Coarer, E., Lisi, F., Perraut, K., Puget, P., Rantakyrö, F., Robbe-Dubois, S., Roussel, A., Tatulli, E., Weigelt, G., Zins, G., Accardo, M., Acke, B., Agabi, K., Altariba, E., Arezki, B., Aristidi, E., Baffa, C., Behrend, J., Blöcker, T., Bonhomme, S., Busoni, S., Cassaing, F., Clausse, J.-M., Colin, J., Connot, C., Delboulbé, A., Domiciano de Souza, A., Driebe, T., Feautrier, P., Ferruzzi, D., Forveille, T., Fossat, E., Foy, R., Fraix-Burnet, D., Gallardo, A., Giani, E., Gil, C., Glentzlin, A., Heiden, M., Heininger, M., Hernandez Utrera, O., Hofmann, K.-H., Kamm, D., Kiekebusch, M., Kraus, S., Le Contel, D., Le Contel, J.-M., Lesourd, T., Lopez, B., Lopez, M., Magnard, Y., Marconi, A., Mars, G., Martinot-Lagarde, G., Mathias, P., Mège, P., Monin, J.-L., Mouillet, D., Nussbaum, E., Ohnaka, K., Pacheco, J., Perrier, C., Rabbia, Y., Rebattu, S., Reynaud, F., Richichi, A., Robini, A., Sacchettini, M., Schertl, D., Schöller, M., Solscheid, W., Spang, A., Stee, P., Stefanini, P., Tasso, D., Testi, L., von der Lühe, O., Valtier, J.-C., Vannier, M., and Ventura, N.

Abstract

Context.Interferometry can provide spatially resolvedobservations of massive star binary systems and their colliding winds, which thus far have been studied mostly with spatially unresolvedobservations.

Published
2007
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8. AMBER/VLTI interferometric observations of the recurrent Nova RS Ophiuchii 5.5 days after outburst*

Author

Chesneau, O., Nardetto, N., Millour, F., Hummel, C., Domiciano de Souza, A., Bonneau, D., Vannier, M., Rantakyrö, F., Spang, A., Malbet, F., Mourard, D., Bode, M. F., O'Brien, T. J., Skinner, G., Petrov, R. G., Stee, P., Tatulli, E., Vakili, F., Chesneau, O., Nardetto, N., Millour, F., Hummel, C., Domiciano de Souza, A., Bonneau, D., Vannier, M., Rantakyrö, F., Spang, A., Malbet, F., Mourard, D., Bode, M. F., O'Brien, T. J., Skinner, G., Petrov, R. G., Stee, P., Tatulli, E., and Vakili, F.

Abstract

Aims.We report on spectrally dispersed interferometric AMBER/VLTI observations of the recurrent nova RS Ophfive days after the discovery of its outburst on 2006 Feb. 12.

Published
2007
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9. First sky validation of an optical polarimetric interferometer

Author

Rousselet-Perraut, K., Le Bouquin, J. B., Mourard, D., Vakili, F., Chesneau, O., Bonneau, D., Chevassut, J. L., Crocherie, A., Glentzlin, A., Jankov, S., Ménardi, S., Petrov, R., Stehlé, C., Rousselet-Perraut, K., Le Bouquin, J. B., Mourard, D., Vakili, F., Chesneau, O., Bonneau, D., Chevassut, J. L., Crocherie, A., Glentzlin, A., Jankov, S., Ménardi, S., Petrov, R., and Stehlé, C.

Abstract

Aims.We present the first lab and sky validation of spectro-polarimetric equipment put at the combined focus of an optical long-baseline interferometer. We tested the polarimetric mode designed for the visible GI2T Interferometer to offer spectropolarimetric diagnosis at the milliarcsecond scale.

Published
2006
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10. Wavefront outer scale deduced from interferometric dispersed fringes

Author

Maire, J., Ziad, A., Borgnino, J., Mourard, D., Martin, F., Jankov, S., Bonneau, D., Patru, F., Maire, J., Ziad, A., Borgnino, J., Mourard, D., Martin, F., Jankov, S., Bonneau, D., and Patru, F.

Abstract

In addition to site characterization, measurements of critical atmospheric parameters are required to design and to optimize future adaptive optic systems and long-baseline interferometers. It is possible to estimate seeing conditions by processing data obtained with existing High Angular Resolution instruments. We report the results of joint observations with the GI2T interferometer and the GSM site-testing monitor performed over a period of several nights. We compared estimates of the wavefront outer scale done at various baselines as well as the seeing (Fried's parameter). We processed interferometric data by calculating power spectra of dispersed fringe images. Deduced measurements of the optical path difference lead to the estimates of the outer scale. We found that the outer scale values obtained from the GI2T data are mostly in the 5-30 m range, in good agreement with GSM measurements.

Published
2006
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11. CCD measurements of visual double stars made with the 74 cm and 50 cm refractors of the Nice Observatory (2nd series)*

Author

Gili, R., Bonneau, D., Gili, R., and Bonneau, D.

Abstract

We present 619 measurements of 606 visual double stars made by CCD imaging from 1996 to 1999 with the 74 cm and 50 cm refractors of the Nice observatory. Angular separation, position angle and magnitude difference are given. Magnitude differences estimated from CCD images are compared with magnitude differences given in the Hipparcos catalog. The residuals in angular separation and position angle are computed for binaries with known orbit.

Published
2001
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12. ??Centauri: a new binary Be star detected by VLTI/AMBER spectro-interferometry

Author

Meilland, A., Millour, F., Stee, Ph., Spang, A., Petrov, R., Bonneau, D., Perraut, K., and Massi, F.

Abstract

Aims. We study the Be star ??Cen circumstellar disk using long-baseline interferometry which is the only observing technique capable of resolving spatially and spectroscopically objects smaller than 5 mas in the H and?K?band.Methods. We used the VLTI/AMBER instrument on January?6, 8, and?9,?2008, in the H and?K?bands to complete low (35) and medium (1500) spectral resolution observations.Results. We detected an oscillation in the visibility curve plotted as a function of the spatial frequency which is a clear signature of a companion around ??Cen. Our best-fit soltution infers a binary separation of 68.7?mas, a companion flux contribution in the K?band of about 7% of the total flux, a PA of 117.5?, and an envelope flux around the Be primary that contributes up to about 50% of the total flux, in agreement with our Spectral Energy Distribution (SED) fit. The envelope size is estimated to be 1.6?mas in K but no departure from spherical symmetry is detected.

Published
2008

13. Research NoteSIDONIE: A gateway for visual double stars studies

Author

Le Contel, D., Valtier, J.-C., Bonneau, D., Le Contel, D., Valtier, J.-C., and Bonneau, D.

Abstract

A database on visual binaries is presented. It contains measurements on 12750 visual binaries with less than 2''of separation or with large proper motion north of -10 degrees of declination. It contains also bibliographic references and published orbits for 851 stars. The SIDONIE database is implemented on the Web and allows astronomers to prepare new observations, find data to calculate new orbits or obtain statistical information on the stars in the database.

Published
2001
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14. SearchCal: a virtual observatory tool for searching calibrators in optical long baseline interferometry

Author

Bonneau, D., Clausse, J.-M., Delfosse, X., Mourard, D., Cetre, S., Chelli, A., Cruzalèbes, P., Duvert, G., Zins, G., Bonneau, D., Clausse, J.-M., Delfosse, X., Mourard, D., Cetre, S., Chelli, A., Cruzalèbes, P., Duvert, G., and Zins, G.

Abstract

Context.In long baseline interferometry, the raw fringe contrast must be calibrated to obtain the true visibility and then those observables that can be interpreted in terms of astrophysical parameters. The selection of suitable calibration stars is crucial for obtaining the ultimate precision of interferometric instruments like the VLTI. Potential calibrators must have spectro-photometric properties and a sky location close to those of the scientific target.

Published
2006
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15. Chromosphere of K giant stars

Author

Berio, P., Merle, T., Thévenin, F., Bonneau, D., Mourard, D., Chesneau, O., Delaa, O., Ligi, R., Nardetto, N., Perraut, K., Pichon, B., Stee, P., Tallon-Bosc, I., Clausse, J. M., Spang, A., McAlister, H., ten Brummelaar, T., Sturmann, J., Sturmann, L., Turner, N., Farrington, C., and Goldfinger, P. J.

Abstract

Context.Interferometers provide accurate diameter measurements of stars by analyzing both the continuum and the lines formed in photospheres and chromospheres. Tests of the geometrical extent of the chromospheres are therefore possible by comparing the estimated radius in the continuum of the photosphere and the estimated radii in chromospheric lines.

Published
2011
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16. SearchCal: a Virtual Observatory tool for searching calibrators in optical long-baseline interferometry

Author

Bonneau, D., Delfosse, X., Mourard, D., Lafrasse, S., Mella, G., Cetre, S., Clausse, J.-M., and Zins, G.

Abstract

Context.In long-baseline interferometry, images or astrophysical parameters are obtained from the raw fringe contrast after a careful calibration process. We have already developed the software (SearchCal) to select suitable bright calibration stars (V≤ 10; K≤ 5.0) for obtaining the ultimate precision of current interferometric instruments like the VLTI. With the expected gain in sensitivity of AMBER and PRIMA on the VLTI, the need for fainter calibrators should now be adressed.

Published
2011
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17. A large Hαline forming region for the massive interacting binaries βLyrae and υSagitarii

Author

Bonneau, D., Chesneau, O., Mourard, D., Bério, Ph., Clausse, J. M., Delaa, O., Marcotto, A., Perraut, K., Roussel, A., Spang, A., Stee, Ph., Tallon-Bosc, I., McAlister, H., ten Brummelaar, T., Sturmann, J., Sturmann, L., Turner, N., Farrington, C., and Goldfinger, P. J.

Abstract

Aims.This study aims at constraining the properties of two interacting binary systems by measuring their continuum-forming region in the visible and the forming regions of some emission lines, in particular Hα, using optical interferometry.

Published
2011
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18. The binary Be star δScorpii at high spectral and spatial resolution⋆

Author

Meilland, A., Delaa, O., Stee, Ph., Kanaan, S., Millour, F., Mourard, D., Bonneau, D., Petrov, R., Nardetto, N., Marcotto, A., Roussel, A., Clausse, J. M., Perraut, K., McAlister, H., ten Brummelaar, T., Sturmann, J., Sturmann, L., Turner, N., Ridgway, S. T., Farrington, C., and Goldfinger, P. J.

Abstract

Context.Classical Be stars are hot non-supergiant stars surrounded by a gaseous circumstellar disk that is responsible for the observed IR-excess and emission lines. The influence of binarity on these phenomena remains controversial.

Published
2011
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19. Spatio-spectral encoding of fringes in optical long-baseline interferometry

Author

Mourard, D., Bério, Ph., Perraut, K., Ligi, R., Blazit, A., Clausse, J. M., Nardetto, N., Spang, A., Tallon-Bosc, I., Bonneau, D., Chesneau, O., Delaa, O., Millour, F., Stee, P., Le Bouquin, J. B., ten Brummelaar, T., Farrington, C., Goldfinger, P. J., and Monnier, J. D.

Abstract

Context.One of the main challenges of optical stellar interferometers is to increase the number of telescopes in the recombining unit to provide a larger number of measurements and an improved imaging capability. At the same time there is a need to preserve the spectroscopic capabilities, which leads to complex recombining schemes that may inhibit development.

Published
2011
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20. Kinematics and geometrical study of the Be stars 48 Persei and ψPersei with the VEGA/CHARA interferometer

Author

Delaa, O., Stee, Ph., Meilland, A., Zorec, J., Mourard, D., Bério, Ph., Bonneau, D., Chesneau, O., Clausse, J. M., Cruzalebes, P., Perraut, K., Marcotto, A., Roussel, A., Spang, A., McAlister, H., ten Brummelaar, T., Sturmann, J., Sturmann, L., Turner, N., Farrington, C., and Goldfinger, P. J.

Abstract

Context.Five different physical processes might be responsible for the formation of decretion disks around Be stars: fast rotation of the star, stellar pulsations, binarity, stellar winds, and magnetic fields. Our observations indicate that fast rotation seems to produce a disk in Keplerian rotation, at least in the specific case of the two stars observed. We do not know if this observational result is a generality or not.

Published
2011
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21. The fundamental parameters of the roAp star γEquulei

Author

Perraut, K., Brandão, I., Mourard, D., Cunha, M., Bério, Ph., Bonneau, D., Chesneau, O., Clausse, J. M., Delaa, O., Marcotto, A., Roussel, A., Spang, A., Stee, Ph., Tallon-Bosc, I., McAlister, H., ten Brummelaar, T., Sturmann, J., Sturmann, L., Turner, N., Farrington, C., and Goldfinger, P. J.

Abstract

Context.A precise comparison of the predicted and observed locations of stars in the H-R diagram is needed when testing stellar interior theoretical models. For doing this, one must rely on accurate, observed stellar fundamental parameters (mass, radius, luminosity, and abundances).

Published
2011
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22. An investigation of the close environment of βCephei with the VEGA/CHARA interferometer

Author

Nardetto, N., Mourard, D., Tallon-Bosc, I., Tallon, M., Berio, P., Chapellier, E., Bonneau, D., Chesneau, O., Mathias, P., Perraut, K., Stee, P., Blazit, A., Clausse, J. M., Delaa, O., Marcotto, A., Millour, F., Roussel, A., Spang, A., McAlister, H., ten Brummelaar, T., Sturmann, J., Sturmann, L., Turner, N., Farrington, C., and Goldfinger, P. J.

Abstract

Context.High-precision interferometric measurements of pulsating stars help to characterize their close environment. In 1974, a close companion was discovered around the pulsating star βCep using the speckle interferometry technique, and features at the limit of resolution (20 milli-arcsec or mas) of the instrument were mentioned that may be due to circumstellar material. βCep has a magnetic field that might be responsible for a spherical shell or ring-like structure around the star as described by the MHD models.

Published
2011
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23. Time, spatial, and spectral resolution of the Hαline-formation region of Deneb and Rigel with the VEGA/CHARA interferometer *

Author

Chesneau, O., Dessart, L., Mourard, D., Bério, Ph., Buil, Ch., Bonneau, D., Borges Fernandes, M., Clausse, J. M., Delaa, O., Marcotto, A., Meilland, A., Millour, F., Nardetto, N., Perraut, K., Roussel, A., Spang, A., Stee, P., Tallon-Bosc, I., McAlister, H., ten Brummelaar, T., Sturmann, J., Sturmann, L., Turner, N., Farrington, C., and Goldfinger, P. J.

Abstract

Context. BA-type supergiants are amongst the most optically-bright stars. They are observable in extragalactic environments, hence potential accurate distance indicators.

Published
2010
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24. Angular diameter estimation of interferometric calibrators

Author

Cruzalèbes, P., Jorissen, A., Sacuto, S., and Bonneau, D.

Abstract

Context. Accurate long-baseline interferometric measurements require careful calibration with reference stars. Small calibrators with high angular diameter accuracy ensure the true visibility uncertainty to be dominated by the measurement errors.Aims. We review some indirect methods for estimating angular diameter, using various types of input data. Each diameter estimate, obtained for the test-case calibrator star λGru, is compared with the value 2.71 mas found in the Bordé calibrator catalogue published in 2002.Methods. Angular size estimations from spectral type, spectral index, in-band magnitude, broadband photometry, and spectrophotometry give close estimates of the angular diameter, with slightly variable uncertainties. Fits on photometry and spectrophotometry need physical atmosphere models with “plausible” stellar parameters. Angular diameter uncertainties were estimated by means of residual bootstrapping confidence intervals. All numerical results and graphical outputs presented in this paper were obtained using the routines developed under PV-WAVE®, which compose the modular software suite SPIDAST, created to calibrate and interprete spectroscopic and interferometric measurements, particularly those obtained with VLTI-AMBER.Results. The final angular diameter estimate 2.70 mas of λGru, with 68% confidence interval 2.65–2.81 mas, is obtained by fit of the MARCS model on the ISO-SWS 2.38–27.5 μm spectrum, with the stellar parameters Te= 4250 K, log g= 2.0, z= 0.0 dex, $\mathcal{M}$= 1.0 $\mathcal{M}_{\odot}$, and $\xi_{\rm t}$= 2.0 km s-1.

Published
2010

25. The Hαline forming region of AB Aurigae spatially resolved at sub-AU with the VEGA/CHARA spectro-interferometer

Author

Rousselet-Perraut, K., Benisty, M., Mourard, D., Rajabi, S., Bacciotti, F., Bério, Ph., Bonneau, D., Chesneau, O., Clausse, J. M., Delaa, O., Marcotto, A., Roussel, A., Spang, A., Stee, Ph., Tallon-Bosc, I., McAlister, H., ten Brummelaar, T., Sturmann, J., Sturmann, L., Turner, N., Farrington, C., and Goldfinger, P. J.

Abstract

Context. A crucial issue in star formation is to understand the physical mechanism by which mass is accreted onto and ejected by a young star. To derive key constraints on the launching point of the jets and on the geometry of the winds, the visible spectro-polarimeter VEGA installed on the CHARA optical array can be an efficient means of probing the structure and the kinematics of the hot circumstellar gas at sub-AU.Aims. For the first time, we observed the Herbig Ae star AB Aur in the Hαemission line, using the VEGA low spectral resolution (R= 1700) on two baselines of the array.Methods. We computed and calibrated the spectral visibilities of AB Aur between 610 nm and 700 nm in spectral bands of 20.4 nm. To simultaneously reproduce the line profile and the inferred visibility around Hα, we used a 1D radiative transfer code (RAMIDUS/PROFILER) that calculates level populations for hydrogen atoms in a spherical geometry and that produces synthetic spectro-interferometric observables.Results. We clearly resolved AB Aur in the Hαline and in a part of the continuum, even at the smallest baseline of 34 m. The small P-Cygni absorption feature is indicative of an outflow but could not be explained by a spherical stellar wind model. Instead, it favors a magneto-centrifugal X-disk or disk-wind geometry. The fit of the spectral visibilities from 610 to 700 nm could not be accounted for by a wind alone, so another component inducing a visibility modulation around Hαneeded to be considered. We thus considered a brightness asymmetry possibly caused by large-scale nebulosity or by the known spiral structures. Conclusions. Thanks to the unique capabilities of VEGA, we managed to simultaneously record for the first time a spectrum at a resolution of 1700 and spectral visibilities in the visible range on a target as faint as mV= 7.1. It was possible to rule out a spherical geometry for the wind of AB Aur and provide realistic solutions to account for the Hαemission compatible with magneto-centrifugal acceleration. It was difficult, however, to determine the exact morphology of the wind because of the surrounding asymmetric nebulosity. The study illustrates the advantages of optical interferometry and motivates observations of other bright young stars in the same way to shed light on the accretion/ejection processes.

Published
2010

26. Angular diameter estimation of interferometric calibrators

Author

Cruzalèbes, P., Jorissen, A., Sacuto, S., and Bonneau, D.

Abstract

Context. Accurate long-baseline interferometric measurements require careful calibration with reference stars. Small calibrators with high angular diameter accuracy ensure the true visibility uncertainty to be dominated by the measurement errors.

Published
2010
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27. The Hαline forming region of AB Aurigae spatially resolved at sub-AU with the VEGA/CHARA spectro-interferometer

Author

Rousselet-Perraut, K., Benisty, M., Mourard, D., Rajabi, S., Bacciotti, F., Bério, Ph., Bonneau, D., Chesneau, O., Clausse, J. M., Delaa, O., Marcotto, A., Roussel, A., Spang, A., Stee, Ph., Tallon-Bosc, I., McAlister, H., ten Brummelaar, T., Sturmann, J., Sturmann, L., Turner, N., Farrington, C., and Goldfinger, P. J.

Abstract

Context. A crucial issue in star formation is to understand the physical mechanism by which mass is accreted onto and ejected by a young star. To derive key constraints on the launching point of the jets and on the geometry of the winds, the visible spectro-polarimeter VEGA installed on the CHARA optical array can be an efficient means of probing the structure and the kinematics of the hot circumstellar gas at sub-AU.

Published
2010
Full Text
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