Magnetic fields of young solar twins
Aims. The goal of this work is to study the magnetic fields of six young solar-analogue stars both individually, and collectively, to search for possible magnetic field trends with age. If such trends are found, they can be used to understand magnetism in the context of stellar evolution of solar-li...
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ftaaltouniv:oai:aaltodoc.aalto.fi:123456789/32829 2024-04-28T08:41:38+00:00 Magnetic fields of young solar twins Rosén, L. Kochukhov, O. Hackman, T. Lehtinen, J. Department of Computer Science Centre of Excellence Research on Solar Long-Term Variability and Effects, ReSoLVE Uppsala University University of Helsinki Aalto-yliopisto Aalto University 2016-09-01 24 1-24 application/pdf https://aaltodoc.aalto.fi/handle/123456789/32829 https://doi.org/10.1051/0004-6361/201628443 en eng Astronomy and Astrophysics Volume 593 Rosén, L, Kochukhov, O, Hackman, T & Lehtinen, J 2016, ' Magnetic fields of young solar twins ', Astronomy and Astrophysics, vol. 593, A35, pp. 1-24 . https://doi.org/10.1051/0004-6361/201628443 0004-6361 1432-0746 PURE UUID: 83c111aa-370e-4507-898d-c13df9359ebb PURE ITEMURL: https://research.aalto.fi/en/publications/83c111aa-370e-4507-898d-c13df9359ebb PURE LINK: http://www.scopus.com/inward/record.url?scp=84986275902&partnerID=8YFLogxK PURE FILEURL: https://research.aalto.fi/files/26498195/aa28443_16.pdf https://aaltodoc.aalto.fi/handle/123456789/32829 URN:NBN:fi:aalto-201808014230 doi:10.1051/0004-6361/201628443 openAccess Magnetic fields Polarization Stars: general Stars: late-type A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä publishedVersion 2016 ftaaltouniv https://doi.org/10.1051/0004-6361/201628443 2024-04-10T00:19:42Z Aims. The goal of this work is to study the magnetic fields of six young solar-analogue stars both individually, and collectively, to search for possible magnetic field trends with age. If such trends are found, they can be used to understand magnetism in the context of stellar evolution of solar-like stars and to understand the past of the Sun and the solar system. This is also important for the atmospheric evolution of the inner planets, Earth in particular. Methods. We used Stokes IV data from two different spectropolarimeters, NARVAL and HARPSpol. The least-squares deconvolution multi-line technique was used to increase the signal-to-noise ratio of the data. We then applied a modern Zeeman-Doppler imaging code in order to reconstruct the magnetic topology of all stars and the brightness distribution of one of our studied stars. Results. Our results show a significant decrease in the magnetic field strength and energy as the stellar age increases from 100 Myr to 250 Myr, while there is no significant age dependence of the mean magnetic field strength for stars with ages 250-650 Myr. The spread in the mean field strength between different stars is comparable to the scatter between different observations of individual stars. The meridional field component is weaker than the radial and azimuthal field components in 15 of the 16 magnetic maps. It turns out that 89-97% of the magnetic field energy is contained in l = 1 - 3. There is also no clear trend with age and distribution of field energy into poloidal/toroidal and axisymmetric/non-axisymmetric components within the sample. The two oldest stars in this study show an octupole component that is twice as strong as the quadrupole component. This is only seen in 1 of the 13 maps of the younger stars. One star, χ1 Ori, displays two field polarity switches during almost 5 yr of observations suggesting a magnetic cycle length of 2, 6, or 8 yr. Peer reviewed Article in Journal/Newspaper narval narval Aalto University Publication Archive (Aaltodoc) Astronomy & Astrophysics 593 A35 |
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Aalto University Publication Archive (Aaltodoc) |
op_collection_id |
ftaaltouniv |
language |
English |
topic |
Magnetic fields Polarization Stars: general Stars: late-type |
spellingShingle |
Magnetic fields Polarization Stars: general Stars: late-type Rosén, L. Kochukhov, O. Hackman, T. Lehtinen, J. Magnetic fields of young solar twins |
topic_facet |
Magnetic fields Polarization Stars: general Stars: late-type |
description |
Aims. The goal of this work is to study the magnetic fields of six young solar-analogue stars both individually, and collectively, to search for possible magnetic field trends with age. If such trends are found, they can be used to understand magnetism in the context of stellar evolution of solar-like stars and to understand the past of the Sun and the solar system. This is also important for the atmospheric evolution of the inner planets, Earth in particular. Methods. We used Stokes IV data from two different spectropolarimeters, NARVAL and HARPSpol. The least-squares deconvolution multi-line technique was used to increase the signal-to-noise ratio of the data. We then applied a modern Zeeman-Doppler imaging code in order to reconstruct the magnetic topology of all stars and the brightness distribution of one of our studied stars. Results. Our results show a significant decrease in the magnetic field strength and energy as the stellar age increases from 100 Myr to 250 Myr, while there is no significant age dependence of the mean magnetic field strength for stars with ages 250-650 Myr. The spread in the mean field strength between different stars is comparable to the scatter between different observations of individual stars. The meridional field component is weaker than the radial and azimuthal field components in 15 of the 16 magnetic maps. It turns out that 89-97% of the magnetic field energy is contained in l = 1 - 3. There is also no clear trend with age and distribution of field energy into poloidal/toroidal and axisymmetric/non-axisymmetric components within the sample. The two oldest stars in this study show an octupole component that is twice as strong as the quadrupole component. This is only seen in 1 of the 13 maps of the younger stars. One star, χ1 Ori, displays two field polarity switches during almost 5 yr of observations suggesting a magnetic cycle length of 2, 6, or 8 yr. Peer reviewed |
author2 |
Department of Computer Science Centre of Excellence Research on Solar Long-Term Variability and Effects, ReSoLVE Uppsala University University of Helsinki Aalto-yliopisto Aalto University |
format |
Article in Journal/Newspaper |
author |
Rosén, L. Kochukhov, O. Hackman, T. Lehtinen, J. |
author_facet |
Rosén, L. Kochukhov, O. Hackman, T. Lehtinen, J. |
author_sort |
Rosén, L. |
title |
Magnetic fields of young solar twins |
title_short |
Magnetic fields of young solar twins |
title_full |
Magnetic fields of young solar twins |
title_fullStr |
Magnetic fields of young solar twins |
title_full_unstemmed |
Magnetic fields of young solar twins |
title_sort |
magnetic fields of young solar twins |
publishDate |
2016 |
url |
https://aaltodoc.aalto.fi/handle/123456789/32829 https://doi.org/10.1051/0004-6361/201628443 |
genre |
narval narval |
genre_facet |
narval narval |
op_relation |
Astronomy and Astrophysics Volume 593 Rosén, L, Kochukhov, O, Hackman, T & Lehtinen, J 2016, ' Magnetic fields of young solar twins ', Astronomy and Astrophysics, vol. 593, A35, pp. 1-24 . https://doi.org/10.1051/0004-6361/201628443 0004-6361 1432-0746 PURE UUID: 83c111aa-370e-4507-898d-c13df9359ebb PURE ITEMURL: https://research.aalto.fi/en/publications/83c111aa-370e-4507-898d-c13df9359ebb PURE LINK: http://www.scopus.com/inward/record.url?scp=84986275902&partnerID=8YFLogxK PURE FILEURL: https://research.aalto.fi/files/26498195/aa28443_16.pdf https://aaltodoc.aalto.fi/handle/123456789/32829 URN:NBN:fi:aalto-201808014230 doi:10.1051/0004-6361/201628443 |
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openAccess |
op_doi |
https://doi.org/10.1051/0004-6361/201628443 |
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Astronomy & Astrophysics |
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593 |
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A35 |
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1797571871991922688 |