Reference : Ground-based observations of the beta Cephei CoRoT main target HD 180 642: abundance ...
Scientific journals : Article
Physical, chemical, mathematical & earth Sciences : Space science, astronomy & astrophysics
http://hdl.handle.net/2268/31640
Ground-based observations of the beta Cephei CoRoT main target HD 180 642: abundance analysis and mode identification
English
Briquet, Maryline mailto [Instituut voor Sterrenkunde, Katholieke Universiteit Leuven, Celestijnenlaan 200 D, 3001 Leuven, Belgium]
Uytterhoeven, K. [INAF - Osservatorio Astronomico di Brera, via E. Bianchi 46, 23807 Merate, Italy ; Instituto de Astrofísica de Canarias, Calle via Láctea s/n, 38205 La Laguna, TF, Spain]
Morel, Thierry mailto [Université de Liège - ULg > Département d'astrophys., géophysique et océanographie (AGO) > Groupe d'astrophysique des hautes énergies (GAPHE) >]
Aerts, C. [Instituut voor Sterrenkunde, Katholieke Universiteit Leuven, Celestijnenlaan 200 D, 3001 Leuven, Belgium; Department of Astrophysics, University of Nijmegen, IMAPP, PO Box 9010, 6500 GL Nijmegen, The Netherlands]
De Cat, P. [Koninklijke Sterrenwacht van België, Ringlaan 3, 1180 Brussel, Belgium]
Mathias, P. [UMR 6525 H. Fizeau, UNS, CNRS, OCA, Campus Valrose, 06108 Nice Cedex 2, France]
Lefever, K. [Instituut voor Sterrenkunde, Katholieke Universiteit Leuven, Celestijnenlaan 200 D, 3001 Leuven, Belgium; BIRA-IASB, Ringlaan 3, 1180 Brussel, Belgium]
Miglio, Andrea mailto [Université de Liège - ULg > Département d'astrophys., géophysique et océanographie (AGO) > Astrophysique stellaire théorique et astérosismologie >]
Poretti, E. [INAF - Osservatorio Astronomico di Brera, via E. Bianchi 46, 23807 Merate, Italy]
Marti­n-Ruiz, S. [> >]
Paparo, M. [> >]
Rainer, M. [INAF - Osservatorio Astronomico di Brera, via E. Bianchi 46, 23807 Merate, Italy]
Carrier, F. [Instituut voor Sterrenkunde, Katholieke Universiteit Leuven, Celestijnenlaan 200 D, 3001 Leuven, Belgium]
Gutierrez-Soto, J. [> >]
Valtier, J. C. [UMR 6525 H. Fizeau, UNS, CNRS, OCA, Campus Valrose, 06108 Nice Cedex 2, France]
Benko, J. M. [> >]
Bognar, Z. [> >]
Niemczura, E. [Instituut voor Sterrenkunde, Katholieke Universiteit Leuven, Celestijnenlaan 200 D, 3001 Leuven, Belgium; Instytut Astronomiczny Wroclawski, Kopernika 11, 51-622 Wroclaw, Poland]
Amado, P. J. [Instituto de Astrofísica de Andalucía (CSIC), Apdo. 3004, 18080 Granada, Spain]
Suarez, J. C. [> >]
Moya, A. [Instituto de Astrofísica de Andalucía (CSIC), Apdo. 3004, 18080 Granada, Spain]
Rodri­guez-Lopez, C. [> >]
Garrido, R. [Instituto de Astrofísica de Andalucía (CSIC), Apdo. 3004, 18080 Granada, Spain]
1-Oct-2009
Astronomy and Astrophysics
EDP Sciences
506
269-280
Yes (verified by ORBi)
International
0004-6361
1432-0746
Les Ulis
France
[en] stars: abundances ; stars: early-type ; stars: oscillations ; stars: individual: HD 180 642
[en] The known β Cephei star HD 180 642 was observed by the CoRoT satellite in 2007. From the very high-precision light curve, its pulsation frequency spectrum could be derived for the first time (Degroote and collaborators). In this paper, we obtain additional constraints for forthcoming asteroseismic modeling of the target. Our results are based on both extensive ground-based multicolour photometry and high-resolution spectroscopy. We determine T_eff = 24 500± 1000 K and log g = 3.45± 0.15 dex from spectroscopy. The derived chemical abundances are consistent with those for B stars in the solar neighbourhood, except for a mild nitrogen excess. A metallicity Z = 0.0099± 0.0016 is obtained. Three modes are detected in photometry. The degree â is unambiguously identified for two of them: â = 0 and â = 3 for the frequencies 5.48694 d[SUP]-1[/SUP] and 0.30818 d[SUP]-1[/SUP], respectively. The radial mode is non-linear and highly dominant with an amplitude in the U-filter about 15 times larger than the strongest of the other modes. For the third frequency of 7.36673 d[SUP]-1[/SUP] found in photometry, two possibilities remain: â = 0 or 3. In the radial velocities, the dominant radial mode presents a so-called stillstand but no clear evidence of the existence of shocks is observed. Four low-amplitude modes are found in spectroscopy and one of them, with frequency 8.4079 d[SUP]-1[/SUP], is identified as (â ,m)=(3,2). Based on this mode identification, we finally deduce an equatorial rotational velocity of 38± 15 km s[SUP]-1[/SUP]. Based on data gathered with the 1.2m Mercator telescope Roque de los Muchachos, La Palma, the 90cm telescope at Sierra Nevada Observatory, Spain, the 1.5 m telescope at San Pedro Mártir Observatory, Mexico, the 1m RCC and 50 cm telescope at the PiszkéstetÅ Mountain Station of Konkoly Observatory, Hungary, the 2.2 m ESO telescope (ESO Programme 077.D-0311; ESO Large Programme 178.D-0361) at La Silla, Chile, the 1.93 m and 1.52 m telescopes at the Haute-Provence Observatory, France. Current address: Laboratoire AIM, CEA/DSM-CNRS-Université Paris Diderot; CEA, IRFU, SAp, centre de Saclay, 91191 Gif-sur-Yvette, France.
http://hdl.handle.net/2268/31640
10.1051/0004-6361/200912025
http://adsabs.harvard.edu/abs/2009A%26A...506..269B
http://de.arxiv.org/abs/0906.3626

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