Browsing by Author "Kervella, Pierre"

Now showing items 1-14 of 14

    • ALMA observations of anisotropic dust mass loss in the inner circumstellar environment of the red supergiant ... 
      O'Gorman, E.; Vlemmings, W.; Richards, A.; Baudry, A.; De Beck, E.; Decin, L.; Harper, G.; Humphreys, E.; Kervella, Pierre; Khouri, T.; Muller, S. (EDP Sciences, 2015)
      The processes leading to dust formation and the subsequent role it plays in driving mass loss in cool evolved stars is an area of intense study. Here we present high resolution ALMA Science Verification data of the continuum ...
    • The Araucaria Project: High-precision orbital parallax and masses of the eclipsing binary TZ Fornacis 
      Gallenne, A.; Pietrzynski, G.; Graczyk, D.; Konorski, P.; Kervella, Pierre; Merand, A.; Gieren, W.; Anderson, R.; Villanova, S. (EDP SCIENCES, 2016)
      Context. Independent distance estimates are particularly useful to check the precision of other distance indicators, while accurate and precise masses are necessary to constrain evolution models. Aims. The goal is to ...
    • Benchmark stars for Gaia Fundamental properties of the Population II star HD 140283 from interferometric, ... 
      Creevey, O.; Thévenin, F.; Berio, P.; Heiter, U.; Von Braun, K.; Mourard, D.; Bigot, L.; Boyajian, T.; Kervella, Pierre; Morel, P.; Pichon, B.; Chiavassa, A.; Nardetto, N.; Perraut, K.; Meilland, A.; Mc Alister, H.; ten Brummelaar, T.; Farrington, C.; Sturmann, J.; Sturmann, L.; Turner, N. (EDP Sciences, 2015)
      Metal-poor halo stars are important astrophysical laboratories that allow us to unravel details about many aspects of astrophysics, including the chemical conditions at the formation of our Galaxy, understanding the processes ...
    • Cepheid distances from the SpectroPhoto-Interferometry of Pulsating Stars (SPIPS) Application to the ... 
      Mérand, A.; Kervella, Pierre; Breitfelder, J.; Gallenne, A.; Coudé du Foresto, V.; Brummelaar, T. A. ten; McAlister, H. A.; Ridgway, S.; Sturmann, L.; Sturmann, J.; Turner, N. H. (EDP Sciences, 2015)
      Context. The parallax of pulsation, and its implementations such as the Baade-Wesselink method and the infrared surface brightness technique, is an elegant method to determine distances of pulsating stars in a quasi-geometrical ...
    • The close circumstellar environment of Betelgeuse III. SPHERE/ZIMPOL imaging polarimetry in the visible 
      Kervella, Pierre; Lagadec, E.; Montarges, M.; Ridgway, S.; Chiavassa, A.; Haubois, X.; Schmid, H.; Langlois, M.; Gallenne, A.; Perrin, G. (EDP SCIENCES, 2016)
      The physical mechanism through which the outgoing material of massive red supergiants is accelerated above the escape velocity is unclear. Thanks to the transparency of its circumstellar envelope, the nearby red supergiant ...
    • The dust disk and companion of the nearby AGB star L-2 Puppis SPHERE/ZIMPOL polarimetric imaging at visible ... 
      Kervella, Pierre; Montargès, M.; Lagadec, E.; Ridgway, S. T.; Haubois, X.; Girard, J. H.; Ohnaka, K.; Perrin, G.; Gallenne, A. (ESO, 2015)
      The bright southern star L-2 Pup is a particularly prominent asymptotic giant branch (AGB) star, located at a distance of only 64 pc. We report new adaptive optics observations of L2 Pup at visible wavelengths with the ...
    • Inspecting the cepheid distance ladder: the Hubble space telescope distance to the SN Ia host Galaxy NGC 5584 
      Javanmardi, Behnam; Mérand, Antoine; Kervella, Pierre; Breuval, Louise; Gallenne, Alexandre; Nardetto, Nicolás; Gieren, Wolfgang; Pietrzyński, Grzegorz; Hocdé, Vincent; Borgniet, Simón (IOP Publishing, 2021)
      The current tension between the direct and the early-universe measurements of the Hubble constant, H0, requires detailed scrutiny of all the data and methods used in the studies on both sides of the debate. The Cepheids ...
    • Investigating Cepheid l Carinae' s cycle-to-cycle variations via contemporaneous velocimetry and ... 
      Anderson, R. I.; Mérand, A.; Kervella, Pierre; Breitfelder, J.; Le Bouquin, J. B.; Eyer, L.; Gallenne, A.; Palaversa, L.; Semaan, T.; Saesen, S.; Mowlavi, N. (Oxford University Press, 2016)
      Baade-Wesselink-type (BW) techniques enable geometric distance measurements of Cepheid variable stars in the Galaxy and the Magellanic clouds. The leading uncertainties involved concern projection factors required to ...
    • Lessons learned from SPHERE for the astrometric strategy of the next generation of exoplanet imaging instruments 
      Maire, Anne-Lise; Langlois, Maud; Delorme, Philippe; Chauvin, Gael; Gratton, Raffaele; Vigan, Arthur; Girard, Julien H.; Wahhaj, Zahed; Pott, Jorg-Uwe; Burtscher, Leonard; Boccaletti, Anthony; Carlotti, Alexis; Henning, Thomas; Kenworthy, Matthew A.; Kervella, Pierre; Rickman, Emily L.; Schmidt, Tobias O. B. (Spie-Soc Photo-Optical Instrumentation Engineers, 2021)
      Measuring the orbits of directly imaged exoplanets requires precise astrometry at the milliarcsec level over long periods of time due to their wide separation to the stars (greater than or similar to 10 au) and long orbital ...
    • Observational calibration of the projection factor of Cepheids 
      Breitfelder, J.; Kervella, Pierre; Mérand, A.; Gallenne, A.; Szabados, L.; Anderson, R. I.; Willson, M.; Le Bouquin, J.-B. (EDP SCIENCES, 2015)
      Context. The distance of pulsating stars, in particular Cepheids, are commonly measured using the parallax of pulsation technique. The different versions of this technique combine measurements of the linear diameter variation ...
    • Pluto’s atmosphere from the 29 June 2015 ground-based stellar occultation at the time of the New Horizons flyby 
      Sicardy, B.; Talbot, J.; Meza, E.; Camargo, J. I. B.; Desmars, J.; Gault, D.; Herald, D.; Kerr, S.; Pavlov, H.; Braga Ribas, F.; Assafin, M.; Benedetti Rossi, G.; Días Oliveira, A.; Gomes Junior, A. R.; Vieira Martins, R.; Bérard, D.; Kervella, Pierre; Lecacheux, J.; Lellouch, E.; Beisker, W.; Dunham, D.; Jelínek, M.; Duffard, R.; Ortiz, J. L.; Castro Tirado, A. J.; Cunniffe, R.; Querel, R.; Yock, P. C.; Cole, A. A.; Giles, A. B.; Hill, K. M.; Beaulieu, J. P.; Harnisch, M.; Jansen, R.; Pennell, A.; Todd, S.; Allen, W. H.; Graham, P. B.; Loader, B.; McKay, G.; Milner, J.; Parker, S.; Barry, M. A.; Bradshaw, J.; Broughton, J.; Davis, L.; Devillepoix, H.; Drummond, J.; Field, L.; Forbes, M.; Giles, D.; Glassey, R.; Groom, R.; Hooper, D.; Horvat, R.; Hudson, G.; Idaczyk, R.; Jenke, D.; Lade, B.; Newman, J.; Nosworthy, P.; Purcell, P.; Skilton, P. F.; Streamer, M.; Unwin, M.; Watanabe, H.; White, G. L.; Watson, D. (The American Astronomical Society, 2016)
      We present results from a multi-chord Pluto stellar occultation observed on 29 June 2015 from New Zealand and Australia. This occurred only two weeks before the NASA New Horizons flyby of the Pluto system and serves as ...
    • Resolving asymmetries along the pulsation cycle of the Mira star X Hydrae 
      Haubois, X.; Wittkowski, M.; Perrin, G.; Kervella, Pierre; Mérand, A.; Thiébaut, E.; Ridgway, S.; Ireland, M.; Scholz, M. (EDP Sciences, 2015)
      Context. The mass-loss process in Mira stars probably occurs in an asymmetric way where dust can form in inhomogeneous circumstellar molecular clumps. Following asymmetries along the pulsation cycle can give us clues about ...
    • Robust high-contrast companion detection from interferometric observations. The CANDID algorithm and an ... 
      Gallenne, A.; Mérand, A.; Kervella, Pierre; Monnier, J. D.; Schaefer, G. H.; Baron, F.; Breitfelder, J.; Le Bouquin, J. B.; Roettenbacher, R. M.; Gieren, W.; Pietrzynski, G.; McAlister, H.; Brummelaar, T. ten; Sturmann, J.; Sturmann, L.; Turner, N.; Ridgway, S.; Kraus, S. (EDP Sciences, 2015)
      Context. Long-baseline interferometry is an important technique to spatially resolve binary or multiple systems in close orbits. By combining several telescopes together and spectrally dispersing the light, it is possible ...
    • VLT/SPHERE- and ALMA-based shape reconstruction of asteroid (3) Juno* 
      Viikinkoski, M.; Kaasalainen, M.; Durech, J.; Carry, B.; Marsset, M.; Fusco, T.; Dumas, C.; Merline, W.; Yang, B.; Berthier, J.; Kervella, Pierre; Vernazza, P. (EDP Sciences, 2015)
      We use the recently released Atacama Large Millimeter Array (ALMA) and VLT/SPHERE science verification data, together with earlier adaptive-optics images, stellar occultation, and lightcurve data to model the 3D shape and ...