Reference : CoRoT high-precision photometry of the B0.5 IV star HD 51756
Scientific journals : Article
Physical, chemical, mathematical & earth Sciences : Space science, astronomy & astrophysics
http://hdl.handle.net/2268/110795
CoRoT high-precision photometry of the B0.5 IV star HD 51756
English
Pápics, P. I. [Instituut voor Sterrenkunde, K.U. Leuven, Celestijnenlaan 200D, 3001, Leuven, Belgium]
Briquet, Maryline mailto [Université de Liège - ULg > Département d'astrophys., géophysique et océanographie (AGO) > Astrophysique stellaire théorique et astérosismologie]
Auvergne, M. [LESIA, UMR8109, Université Pierre et Marie Curie, Université Denis Diderot, Observatoire de Paris, 92195, Meudon Cedex, France]
Aerts, C. [Instituut voor Sterrenkunde, K.U. Leuven, Celestijnenlaan 200D, 3001, Leuven, Belgium; Department of Astrophysics, IMAPP, University of Nijmegen, PO Box 9010, 6500 GL, Nijmegen, The Netherlands]
Degroote, P. [Instituut voor Sterrenkunde, K.U. Leuven, Celestijnenlaan 200D, 3001, Leuven, Belgium]
Niemczura, E. [Instituut voor Sterrenkunde, K.U. Leuven, Celestijnenlaan 200D, 3001, Leuven, Belgium; Instytut Astronomiczny, Uniwersytet Wroclawski, Kopernika 11, 51-622, Wroclaw, Poland]
Vučković, M. [Instituut voor Sterrenkunde, K.U. Leuven, Celestijnenlaan 200D, 3001, Leuven, Belgium; European Southern Observatory (ESO), Alonso de Córdova 3107, Vitacura, Cassilla 19001, Santiago, Chile]
Smolders, K. [Instituut voor Sterrenkunde, K.U. Leuven, Celestijnenlaan 200D, 3001, Leuven, Belgium]
Poretti, E. [Laboratoire AIM, CEA/DSM-CNRS-Université Paris Diderot, CEA, IRFU, SAp, Centre de Saclay, 91191, Gif-sur-Yvette, France]
Rainer, M. [Laboratoire AIM, CEA/DSM-CNRS-Université Paris Diderot, CEA, IRFU, SAp, Centre de Saclay, 91191, Gif-sur-Yvette, France]
Hareter, M. [Institut d'Astrophysique Spatiale, CNRS/Univ. Paris-Sud, Bât. 121, 91405, Orsay Cedex, France]
Baglin, A. [Institut d'Astrophysique Spatiale, CNRS/Univ. Paris-Sud, Bât. 121, 91405, Orsay Cedex, France]
Baudin, F. [INAF - Osservatorio Astronomico di Brera, via E. Bianchi 46, 23807, Merate (LC), Italy]
Catala, C. [LESIA, UMR8109, Université Pierre et Marie Curie, Université Denis Diderot, Observatoire de Paris, 92195, Meudon Cedex, France]
Samadi, R. [LESIA, UMR8109, Université Pierre et Marie Curie, Université Denis Diderot, Observatoire de Paris, 92195, Meudon Cedex, France]
Michel, E. []
1-Apr-2011
Astronomy and Astrophysics
EDP Sciences
528
123
Yes (verified by ORBi)
International
0004-6361
1432-0746
Les Ulis
France
[en] stars: variables: general ; stars: early-type ; stars: oscillations ; stars: individual: HD 51756 ; stars: rotation ; binaries: spectroscopic
[en] Context. OB stars are important constituents for the ecology of the Universe, and there are only a few studies on their pulsational properties detailed enough to provide important feedback on current evolutionary models. <BR /> Aims: Our goal is to analyse and interpret the behaviour present in the CoRoT light curve of the B0.5 IV star HD 51756 observed during the second long run of the space mission and to determine the fundamental stellar parameters from ground-based spectroscopy gathered with the Coralie and Harps instruments after checking for signs of variability and binarity, thus making a step further in mapping the top of the β Cep instability strip. <BR /> Methods: We compared the newly obtained high-resolution spectra with synthetic spectra of late O-type and early B-type stars computed on a grid of stellar parameters. We matched the results with evolutionary tracks to estimate stellar parameters. We used various time series analysis tools to explore the nature of the variations present in the light curve. Additional calculations were carried out based on distance and historical position measurements of the components to impose constraints on the binary orbit. <BR /> Results: We find that HD 51756 is a wide binary with both a slow (vsini ≈ 28 km s[SUP]-1[/SUP]) and a fast (vsini ≈ 170 km s[SUP]-1[/SUP]) early-B rotator whose atmospheric parameters are similar (T[SUB]eff[/SUB] ≈ 30 000 K and log g ≈ 3.75). We are unable to detect pulsation in any of the components, and we interpret the harmonic structure in the frequency spectrum as a sign of rotational modulation, which is compatible with the observed and deduced stellar parameters of both components. <BR /> Conclusions: The non-detection of pulsation modes provides a feedback on the theoretical treatment, given that non-adiabatic computations applied to appropriate stellar models predict the excitation of both pressure and gravity modes for the fundamental parameters of this star. The CoRoT space mission was developed and is operated by the French space agency CNES, with participation of ESA's RSSD and Science Programmes, Austria, Belgium, Brazil, Germany, and Spain.Based on data gathered with Coralie installed on the 1.2 m Euler telescope at La Silla, Chile; and Harps installed on the 3.6 m ESO telescope (ESO Large Programme 182.D-0356) at La Silla, Chile.Appendix A is only available in electronic form at <A href="http://www.aanda.org">http://www.aanda.org</A>
http://hdl.handle.net/2268/110795
10.1051/0004-6361/201016131
http://esoads.eso.org/abs/2011A%26A...528A.123P
http://de.arxiv.org/abs/1101.3428

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