Browsing by Author "c2674129-49cd-48fe-b79d-9770b172379f"

Now showing items 1-14 of 14

    • ALMA observations of the nearby AGB star L-2 Puppis I. Mass of the central star and detection of a candidate planet 
      Kervella, Pierre; Richards, A. M. S.; Decin, L.; McDonald, I.; Montargès, M.; Ohnaka, K. (EDP Sciences, 2016)
      Six billion years from now, while evolving on the asymptotic giant branch (AGB), the Sun will metamorphose from a red giant into a beautiful planetary nebula. This spectacular evolution will impact the solar system planets, ...
    • ALMA observations of the nearby AGB star L2 Puppis II. Gas disk properties derived from 12CO and 13CO J = ... 
      Homan, Ward; Richards, Anita; Decin, Leen; Kervella, Pierre; Koter, Alex de; McDonald, Iain; Ohnaka, Keiichi (EDP Sciences, 2017-05)
      The circumstellar environment of the AGB star L-2 Puppis was observed with ALMA in cycle 3, with a resolution of 15 x 18 mas. The molecular emission shows a differentially rotating disk, inclined to a nearly edge-on position. ...
    • Discovery of a complex linearly polarized spectrum of Betelgeuse dominated by depolarization of the continuum 
      Aurière, M.; López Ariste, A.; Mathias, P.; Lèbre, A.; Josselin, E.; Montargès, M.; Petit, P.; Chiavassa, A.; Paletou, F.; Fabas, N.; Konstantinova Antova, R.; Donati, J. F.; Grunhut, J. H.; Wade, W. A.; Herpin, F.; Kervella, Pierre; Perrin, G.; Tessore, B (EDP Sciences, 2016)
      Context. Betelgeuse is an M supergiant that harbors spots and giant granules at its surface and presents linear polarization of its continuum. Aims. We have previously discovered linear polarization signatures associated ...
    • Hubble space telescope snapshot survey for resolved companions of galactic cepheids: final results 
      Evans, Nancy Remage; Günter, H. Moritz; Bond, Howard E.; Schaefer, Gail H.; Mason, Brian D.; Karovska, Margarita; Tingle, Evan; Wolk, Scott; Engle, Scott; Guinan, Edward; Pillitteri, Ignazio; Proffitt, Charles; Kervella, Pierre; Gallenne, Alexandre; Anderson, Richard I.; Moe, Maxwell (IOP Publishing, 2020)
      Cepheids in multiple systems provide information on the outcome of the formation of massive stars. They can also lead to exotic end-stage objects. This study concludes our survey of 70 galactic Cepheids using the Hubble ...
    • Luminous blue variables: An imaging perspective on their binarity and near environment 
      Martayan, Christophe; Lobel, Alex; Baade, Dietrich; Mehner, Andrea; Rivinius, Thomas; Bo n, Henri M. J.; Girard, Julien; Mawet, Dimitri; Montagnier, Guillaume; Blomme, Ronny; Kervella, Pierre; Sana, Hugues; Štefl, Stanislav; Zorec, Juan; Lacour, Sylvestre; Le Bouquin, Jean-Baptiste; Martins, Fabrice; Mérand, Antoine; Patru, Fabien; Selman, Fernando; Frémat, Yves (ESO, 2016-03)
      Context. Luminous blue variables (LBVs) are rare massive stars with very high luminosity. They are characterized by strong photometric and spectroscopic variability related to transient eruptions. The mechanisms at the ...
    • Mass and p-factor of the type II cepheid OGLE-LMC-T2CEP-098 in a Binary System 
      Pilecki, Bogumil; Gieren, Wolfgang; Smolec, Radoslaw; Pietrzynski, Grzegorz; Thompson, Ian B.; Anderson, Richard I.; Bono, Giuseppe; Soszynski, Igor; Kervella, Pierre; Nardetto, Nicolás; Taormina, Mónica; Stepien, Kazimierz; Wielgorski, Piotr (IOP Publishing, 2017)
      We present the results of a study of the type II Cepheid (P-puls = 4.974 days) in the eclipsing binary system OGLELMC- T2CEP-098 (P-orb = 397.2 days). The Cepheid belongs to the peculiar W Vir group, for which the evolutionary ...
    • Multiplicity of Galactic Cepheids from long-baseline interferometry - III. Sub-percent limits on the relative ... 
      Gallenne, A.; Merand, A.; Kervella, Pierre; Monnier, J. D.; Schaefer, G. H.; Roettenbacher, R. M.; Gieren, W.; Pietrzynski, G.; McAlister, H.; ten Brummelaar, T.; Sturmann, J.; Sturmann, L.; Turner, N.; Anderson, R. I. (2016)
      We report new CHARA/Michigan InfraRed Combiner interferometric observations of the Cepheid archetype delta Cep, which aimed at detecting the newly discovered spectroscopic companion. We reached a maximum dynamic range Delta ...
    • Observational calibration of the projection factor of Cepheids II. Application to nine Cepheids with HST/FGS ... 
      Breitfelder, J.; Mérand, A.; Kervella, Pierre; Gallenne, A.; Szabados, L.; Anderson, R. I.; Le Bouquin, J.-B. (ESO, 2016-03)
      Context. The distance to pulsating stars is classically estimated using the parallax-of-pulsation (PoP) method, which combines spectroscopic radial velocity (RV) measurements and angular diameter (AD) estimates to derive ...
    • Optimized trajectories to the nearest stars using lightweight high velocity photon sails 
      Heller, Rene; Hippke, Michael; Kervella, Pierre (IOP Publishing Ltd, 2017)
      New means of interstellar travel are now being considered by various research teams, assuming lightweight spaceships to be accelerated via either laser or solar radiation to a significant fraction of the speed of light ...
    • Resolved astrometric orbits of ten O-type binaries 
      Le Bouquin, J. -B.; Sana, H.; Gosset, E.; De Becker, M.; Duvert, G.; Absil, O.; Anthonioz, F.; Berger, J. -P.; Ertel, S.; Grellmann, R.; Guieu, S.; Kervella, Pierre; Rabus, M.; Willson, M. (EDP Sciences, 2017-05)
      Aims. Our long-term aim is to derive model-independent stellar masses and distances for long period massive binaries by combining apparent astrometric orbit with double-lined radial velocity amplitudes (SB2). Methods. ...
    • Study of the inner dust envelope and stellar photosphere of the AGB star R Doradus using SPHERE/ZIMPOL 
      Khouri, T.; Maercker, M.; Waters, L. B. F. M.; Vlemmings, Wouter H. T.; Kervella, Pierre; de Koter, A.; Ginski, C.; De Beck, E.; Decin, Leen; Min, M.; Dominik, Carsten; O'Gorman, E.; Schmid, H. M.; Lombaert, R.; Lagadec, E. (EDP Sciences, 2016)
      Context. On the asymptotic giant branch (AGB) low-and intermediate-mass stars eject a large fraction of their envelope, but the mechanism driving these outflows is still poorly understood. For oxygen-rich AGB stars, the ...
    • The close circumstellar environment of Betelgeuse IV. VLTI/PIONIER interferometric monitoring of the photosphere 
      Montargès, M.; Kervella, Pierre; Perrin, G.; Chiavassa, A.; Le Bouquin, J.-B.; Aurière, M.; López Ariste, A.; Mathias, P.; Ridgway, S. T.; Lacour, S.; Haubois, X.; Berger, J.-P. (ESO, 2016)
      Context. The mass-loss mechanism of cool massive evolved stars is poorly understood. The proximity of Betelgeuse makes it an appealing target to study its atmosphere, map the shape of its envelope, and follow the structure ...
    • The Milky Way Cepheid Leavitt law based on Gaia DR2 parallaxes of companion stars and host open cluster populations 
      Breuval, Louise; Kervella, Pierre; Anderson, Richard; Riess, Adam G.; Arenou, Frédéric; Trahin, Boris; Mérand, Antoine; Gallenne, A.; Gieren, Wolfgang; Storm, J.; Bono, Giuseppe; Pietrzynski, Grzegorz; Nardetto, Nicolas; Javanmardi, Behnam; Hocde, Vincent (EDP Sciences, 2020)
      Aims. Classical Cepheids provide the foundation for the empirical extragalactic distance ladder. Milky Way Cepheids are the only stars in this class accessible to trigonometric parallax measurements. However, the parallaxes ...
    • VLTI/PIONIER images the Achernar disk swell 
      Vedova, G. Dalla; Millour, F.; Souza, A. Domiciano de; Petrov, R. G.; Faes, D. Moser; Carciofi, A. C.; Kervella, Pierre; Rivinius, T. (EDP Sciences, 2017-05)
      Context. The mechanism of disk formation around fast-rotating Be stars is not well understood. In particular, it is not clear which mechanisms operate, in addition to fast rotation, to produce the observed variable ejection ...