Reference : Post-AGB stars with hot circumstellar dust: binarity of the low-amplitude pulsators
Scientific journals : Article
Physical, chemical, mathematical & earth Sciences : Space science, astronomy & astrophysics
http://hdl.handle.net/2268/117840
Post-AGB stars with hot circumstellar dust: binarity of the low-amplitude pulsators
English
van Winckel, H. [Instituut voor Sterrenkunde, K.U.Leuven, Celestijnenlaan 200B, 3001 Leuven, Belgium]
Lloyd Evans, T. [SUPA, School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews, Fife, Scotland KY16 9SS, UK]
Briquet, Maryline mailto [Katholieke Universiteit Leuven - KUL > Physics > Institute of Astronomy > >]
De Cat, P. [Instituut voor Sterrenkunde, K.U.Leuven, Celestijnenlaan 200B, 3001 Leuven, Belgium; Royal Observatory of Belgium, Ringlaan 3, 1180 Brussel, Belgium]
Degroote, P. [Instituut voor Sterrenkunde, K.U.Leuven, Celestijnenlaan 200B, 3001 Leuven, Belgium]
De Meester, W. [Instituut voor Sterrenkunde, K.U.Leuven, Celestijnenlaan 200B, 3001 Leuven, Belgium]
De Ridder, J. [Instituut voor Sterrenkunde, K.U.Leuven, Celestijnenlaan 200B, 3001 Leuven, Belgium]
Deroo, P. [Instituut voor Sterrenkunde, K.U.Leuven, Celestijnenlaan 200B, 3001 Leuven, Belgium; Jet Propulsion Laboratory, Caltech, 4800 Oak Grove Drive, Pasadena, CA 91109, USA]
Desmet, M. [Instituut voor Sterrenkunde, K.U.Leuven, Celestijnenlaan 200B, 3001 Leuven, Belgium]
Drummond, R. [Instituut voor Sterrenkunde, K.U.Leuven, Celestijnenlaan 200B, 3001 Leuven, Belgium; Belgian Institute for Space aeronomy, Ringlaan 3, 1180 Brussels, Belgium]
Eyer, L. [Instituut voor Sterrenkunde, K.U.Leuven, Celestijnenlaan 200B, 3001 Leuven, Belgium; Observatoire de Genève, 1290 Sauverny, Switzerland]
Groenewegen, M. A. T. [Instituut voor Sterrenkunde, K.U.Leuven, Celestijnenlaan 200B, 3001 Leuven, Belgium; Royal Observatory of Belgium, Ringlaan 3, 1180 Brussel, Belgium]
Kolenberg, K. [Instituut voor Sterrenkunde, K.U.Leuven, Celestijnenlaan 200B, 3001 Leuven, Belgium; Institut für Astronomie der Universität Wien, Türkenschanzstrasse, 17, 1180 Vienna, Austria]
Kilkenny, D. [Department of Physics, University of the Western Cape, Private Bag X17, Bellville 7535, Western Cape, South Africa]
Ladjal, D. [Instituut voor Sterrenkunde, K.U.Leuven, Celestijnenlaan 200B, 3001 Leuven, Belgium]
Lefever, K. [Instituut voor Sterrenkunde, K.U.Leuven, Celestijnenlaan 200B, 3001 Leuven, Belgium; Belgian Institute for Space aeronomy, Ringlaan 3, 1180 Brussels, Belgium]
Maas, T. [Instituut voor Sterrenkunde, K.U.Leuven, Celestijnenlaan 200B, 3001 Leuven, Belgium]
Marang, F. [South African Astronomical Observatory, PO Box 9, Observatory 7935, South Africa]
Martinez, P. [South African Astronomical Observatory, PO Box 9, Observatory 7935, South Africa]
Østensen, R. H. [Instituut voor Sterrenkunde, K.U.Leuven, Celestijnenlaan 200B, 3001 Leuven, Belgium]
Raskin, G. [Instituut voor Sterrenkunde, K.U.Leuven, Celestijnenlaan 200B, 3001 Leuven, Belgium]
Reyniers, M. [Instituut voor Sterrenkunde, K.U.Leuven, Celestijnenlaan 200B, 3001 Leuven, Belgium; The Royal Meteorological Institute of Belgium, Department Observations, Ringlaan 3, 1180 Brussels, Belgium]
Royer, P. [Instituut voor Sterrenkunde, K.U.Leuven, Celestijnenlaan 200B, 3001 Leuven, Belgium]
Saesen, S. [Instituut voor Sterrenkunde, K.U.Leuven, Celestijnenlaan 200B, 3001 Leuven, Belgium]
Uytterhoeven, K. [Instituut voor Sterrenkunde, K.U.Leuven, Celestijnenlaan 200B, 3001 Leuven, Belgium; Laboratoire AIM, CEA/DSM-CNRS-Université Paris Diderot; CEA, IRFU, SAp, centre de Saclay, 91191 Gif-sur-Yvette, France]
Vanautgaerden, J. [Instituut voor Sterrenkunde, K.U.Leuven, Celestijnenlaan 200B, 3001 Leuven, Belgium]
Vandenbussche, B. [Instituut voor Sterrenkunde, K.U.Leuven, Celestijnenlaan 200B, 3001 Leuven, Belgium]
van Wyk, F. [South African Astronomical Observatory, PO Box 9, Observatory 7935, South Africa]
Vučković, M. [Instituut voor Sterrenkunde, K.U.Leuven, Celestijnenlaan 200B, 3001 Leuven, Belgium]
Waelkens, C. [Instituut voor Sterrenkunde, K.U.Leuven, Celestijnenlaan 200B, 3001 Leuven, Belgium]
Zima, W. [Instituut voor Sterrenkunde, K.U.Leuven, Celestijnenlaan 200B, 3001 Leuven, Belgium]
1-Oct-2009
Astronomy and Astrophysics
EDP Sciences
505
1221-1232
Yes (verified by ORBi)
International
0004-6361
1432-0746
Les Ulis
France
[en] stars: AGB and post-AGB ; stars: binaries: general ; stars: binaries: spectroscopic ; stars: chemically peculiar ; stars: evolution
[en] Context: The influence of binarity on the late stages of stellar evolution remains an open issue. <BR />Aims: While the first binary post-AGB stars were serendipitously discovered, the distinct characteristics of their spectral energy distribution (SED) allowed us to launch a more systematic search for binaries. We selected post-AGB objects, which exhibit a broad dust excess starting either at H or K, pointing to the presence of a gravitationally bound dusty disc in the system. We initiated an extensive multiwavelength study of those systems and here report on our radial velocity and photometric monitoring results for six stars of early F type, which are pulsators of small amplitude. <BR />Methods: To determine the radial velocity of low signal-to-noise ratio time-series data, we constructed dedicated autocorrelation masks based on high signal-to-noise ratio spectra, used in our published chemical studies. The radial velocity variations were analysed in detail to differentiate between pulsational variability and variability caused by orbital motion. When available, the photometric monitoring data were used to complement the time series of radial velocity data and to establish the nature of the pulsation. Finally, orbital minimalisation was performed to constrain the orbital elements. <BR />Results: All of the six objects are binaries with orbital periods ranging from 120 to 1800 days. Five systems have non-circular orbits. The mass functions range from 0.004 to 0.57 M[SUB]&sun;[/SUB] and the companions are probably unevolved objects of (very) low initial mass. We argue that these binaries must have evolved through a phase of strong binary interaction when the primary was a cool supergiant. Although the origin of the circumstellar disc is not well understood, the disc is generally believed to have formed during this strong interaction phase. The eccentric orbits of these highly evolved objects remain poorly understood. In one object, the line-of-sight grazes the edge of the puffed-up inner rim of the disc. <BR />Conclusions: These results corroborate our earlier statement that evolved objects in binary stars create a Keplerian dusty circumbinary disc. With the measured orbits and mass functions, we conclude that the circumbinary discs seem to have a major impact on the evolution of a significant fraction of binary systems. based on observations collected with the Flemish 1.2 m Mercator telescope at Roque de los Muchachos (Spain), the Swiss 1.2 m Euler telescope at La Silla (Chile) and the 0.5 m and 0.75 m telescopes at SAAO (South-Africa). Tables [see full textsee full text]-[see full textsee full text] are only available in electronic form at http://www.aanda.org Postdoctoral fellow of the Fund for Scientific Research, Flanders. Ph.D. student of the Fund for Scientific Research, Flanders.
http://hdl.handle.net/2268/117840
10.1051/0004-6361/200912332
http://esoads.eso.org/abs/2009A%26A...505.1221V
http://de.arxiv.org/abs/0906.4482

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