β Cas: The first δ Scuti star with a dynamo magnetic field
International audience Context. F-type stars are characterised by several physical processes such as different pulsation mechanisms, rotation, convection, diffusion, and magnetic fields. The rapidly rotating δ Scuti star β Cas can be considered as a benchmark star to study the interaction of several...
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ftinsu:oai:HAL:hal-03254112v1 2023-11-05T03:45:27+01:00 β Cas: The first δ Scuti star with a dynamo magnetic field Zwintz, K. Neiner, C. Kochukhov, O. Ryabchikova, T. Pigulski, A. Müllner, M. Steindl, T. Kuschnig, R. Handler, G. Moffat, A. Pablo, H. Popowicz, A. Wade, G. Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA) Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité) 2020-11 https://hal.science/hal-03254112 https://hal.science/hal-03254112/document https://hal.science/hal-03254112/file/aa38210-20.pdf https://doi.org/10.1051/0004-6361/202038210 en eng HAL CCSD EDP Sciences info:eu-repo/semantics/altIdentifier/arxiv/2009.04784 info:eu-repo/semantics/altIdentifier/doi/10.1051/0004-6361/202038210 hal-03254112 https://hal.science/hal-03254112 https://hal.science/hal-03254112/document https://hal.science/hal-03254112/file/aa38210-20.pdf ARXIV: 2009.04784 BIBCODE: 2020A&A.643A.110Z doi:10.1051/0004-6361/202038210 info:eu-repo/semantics/OpenAccess ISSN: 0004-6361 EISSN: 1432-0756 Astronomy and Astrophysics - A&A https://hal.science/hal-03254112 Astronomy and Astrophysics - A&A, 2020, 643, pp.A110. ⟨10.1051/0004-6361/202038210⟩ [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph] info:eu-repo/semantics/article Journal articles 2020 ftinsu https://doi.org/10.1051/0004-6361/202038210 2023-10-11T16:24:41Z International audience Context. F-type stars are characterised by several physical processes such as different pulsation mechanisms, rotation, convection, diffusion, and magnetic fields. The rapidly rotating δ Scuti star β Cas can be considered as a benchmark star to study the interaction of several of these effects. Aims. We investigate the pulsational and magnetic field properties of β Cas. We also determine the star’s apparent fundamental parameters and chemical abundances. Methods. Based on photometric time series obtained from three different space missions (BRITE-Constellation, SMEI, and TESS), we conduct a frequency analysis and investigate the stability of the pulsation amplitudes over four years of observations. We investigate the presence of a magnetic field and its properties using spectropolarimetric observations taken with the Narval instrument by applying the least-squares deconvolution and Zeeman-Doppler imaging techniques. Results. The star β Cas shows only three independent p -mode frequencies down to the few ppm-level; its highest amplitude frequency is suggested to be an n = 3, ℓ = 2, m = 0 mode. Its magnetic field structure is quite complex and almost certainly of a dynamo origin. The atmosphere of β Cas is slightly deficient in iron peak elements and slightly overabundant in C, O, and heavier elements. Conclusions. Atypically for δ Scuti stars, we can only detect three pulsation modes down to exceptionally low noise levels for β Cas. The star is also one of very few δ Scuti pulsators known to date to show a measurable magnetic field and the first δ Scuti star with a dynamo magnetic field. These characteristics make β Cas an interesting target for future studies of dynamo processes in the thin convective envelopes of F-type stars, the transition region between fossil and dynamo fields, and the interaction between pulsations and magnetic field. Article in Journal/Newspaper narval narval Institut national des sciences de l'Univers: HAL-INSU Astronomy & Astrophysics 643 A110 |
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Open Polar |
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Institut national des sciences de l'Univers: HAL-INSU |
op_collection_id |
ftinsu |
language |
English |
topic |
[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph] |
spellingShingle |
[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph] Zwintz, K. Neiner, C. Kochukhov, O. Ryabchikova, T. Pigulski, A. Müllner, M. Steindl, T. Kuschnig, R. Handler, G. Moffat, A. Pablo, H. Popowicz, A. Wade, G. β Cas: The first δ Scuti star with a dynamo magnetic field |
topic_facet |
[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph] |
description |
International audience Context. F-type stars are characterised by several physical processes such as different pulsation mechanisms, rotation, convection, diffusion, and magnetic fields. The rapidly rotating δ Scuti star β Cas can be considered as a benchmark star to study the interaction of several of these effects. Aims. We investigate the pulsational and magnetic field properties of β Cas. We also determine the star’s apparent fundamental parameters and chemical abundances. Methods. Based on photometric time series obtained from three different space missions (BRITE-Constellation, SMEI, and TESS), we conduct a frequency analysis and investigate the stability of the pulsation amplitudes over four years of observations. We investigate the presence of a magnetic field and its properties using spectropolarimetric observations taken with the Narval instrument by applying the least-squares deconvolution and Zeeman-Doppler imaging techniques. Results. The star β Cas shows only three independent p -mode frequencies down to the few ppm-level; its highest amplitude frequency is suggested to be an n = 3, ℓ = 2, m = 0 mode. Its magnetic field structure is quite complex and almost certainly of a dynamo origin. The atmosphere of β Cas is slightly deficient in iron peak elements and slightly overabundant in C, O, and heavier elements. Conclusions. Atypically for δ Scuti stars, we can only detect three pulsation modes down to exceptionally low noise levels for β Cas. The star is also one of very few δ Scuti pulsators known to date to show a measurable magnetic field and the first δ Scuti star with a dynamo magnetic field. These characteristics make β Cas an interesting target for future studies of dynamo processes in the thin convective envelopes of F-type stars, the transition region between fossil and dynamo fields, and the interaction between pulsations and magnetic field. |
author2 |
Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA) Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité) |
format |
Article in Journal/Newspaper |
author |
Zwintz, K. Neiner, C. Kochukhov, O. Ryabchikova, T. Pigulski, A. Müllner, M. Steindl, T. Kuschnig, R. Handler, G. Moffat, A. Pablo, H. Popowicz, A. Wade, G. |
author_facet |
Zwintz, K. Neiner, C. Kochukhov, O. Ryabchikova, T. Pigulski, A. Müllner, M. Steindl, T. Kuschnig, R. Handler, G. Moffat, A. Pablo, H. Popowicz, A. Wade, G. |
author_sort |
Zwintz, K. |
title |
β Cas: The first δ Scuti star with a dynamo magnetic field |
title_short |
β Cas: The first δ Scuti star with a dynamo magnetic field |
title_full |
β Cas: The first δ Scuti star with a dynamo magnetic field |
title_fullStr |
β Cas: The first δ Scuti star with a dynamo magnetic field |
title_full_unstemmed |
β Cas: The first δ Scuti star with a dynamo magnetic field |
title_sort |
β cas: the first δ scuti star with a dynamo magnetic field |
publisher |
HAL CCSD |
publishDate |
2020 |
url |
https://hal.science/hal-03254112 https://hal.science/hal-03254112/document https://hal.science/hal-03254112/file/aa38210-20.pdf https://doi.org/10.1051/0004-6361/202038210 |
genre |
narval narval |
genre_facet |
narval narval |
op_source |
ISSN: 0004-6361 EISSN: 1432-0756 Astronomy and Astrophysics - A&A https://hal.science/hal-03254112 Astronomy and Astrophysics - A&A, 2020, 643, pp.A110. ⟨10.1051/0004-6361/202038210⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/arxiv/2009.04784 info:eu-repo/semantics/altIdentifier/doi/10.1051/0004-6361/202038210 hal-03254112 https://hal.science/hal-03254112 https://hal.science/hal-03254112/document https://hal.science/hal-03254112/file/aa38210-20.pdf ARXIV: 2009.04784 BIBCODE: 2020A&A.643A.110Z doi:10.1051/0004-6361/202038210 |
op_rights |
info:eu-repo/semantics/OpenAccess |
op_doi |
https://doi.org/10.1051/0004-6361/202038210 |
container_title |
Astronomy & Astrophysics |
container_volume |
643 |
container_start_page |
A110 |
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1781708010890985472 |