Direct evidence of a full dipole flip during the magnetic cycle of a sun-like star
Article
Article Title | Direct evidence of a full dipole flip during the magnetic cycle of a sun-like star |
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ERA Journal ID | 1050 |
Article Category | Article |
Authors | Boro Saikia, S. (Author), Lueftinger, T. (Author), Jeffers, S. V. (Author), Folsom, C. P. (Author), See, V. (Author), Petit, P. (Author), Marsden, S. C. (Author), Vidotto, A. A. (Author), Morin, J. (Author), Reiners, A. (Author) and Guedel, M. (Author) |
Journal Title | Astronomy and Astrophysics: a European journal |
Journal Citation | 620, pp. 1-12 |
Article Number | L11 |
Number of Pages | 12 |
Year | 2018 |
Publisher | EDP Sciences |
Place of Publication | France |
ISSN | 0004-6361 |
1432-0746 | |
Digital Object Identifier (DOI) | https://doi.org/10.1051/0004-6361/201834347 |
Web Address (URL) | https://www.aanda.org/articles/aa/full_html/2018/12/aa34347-18/aa34347-18.html |
Abstract | Context. The behaviour of the large-scale dipolar field, during a star’s magnetic cycle, can provide valuable insight into the stellar dynamo and associated magnetic field manifestations such as stellar winds. Aims. We investigate the temporal evolution of the dipolar field of the K dwarf 61 Cyg A using spectropolarimetric observations covering nearly one magnetic cycle equivalent to two chromospheric activity cycles. Methods. The large-scale magnetic field geometry is reconstructed using Zeeman Doppler imaging, a tomographic inversion technique. Additionally, the chromospheric activity is also monitored. Results. The observations provide an unprecedented sampling of the large-scale field over a single magnetic cycle of a star other than the Sun. Our results show that 61 Cyg A has a dominant dipolar geometry except at chromospheric activity maximum. The dipole axis migrates from the southern to the northern hemisphere during the magnetic cycle. It is located at higher latitudes at chromospheric Conclusions. The behaviour of the large-scale dipolar field during the magnetic cycle resembles the solar magnetic cycle. Our results are further confirmation that 61 Cyg A indeed has a large-scale magnetic geometry that is comparable to the Sun’s, despite being a slightly older and cooler K dwarf. |
Keywords | stars; magnetic field; solar-type; imaging |
ANZSRC Field of Research 2020 | 510109. Stellar astronomy and planetary systems |
Byline Affiliations | University of Vienna, Austria |
University of Gottingen, Germany | |
University of Toulouse, France | |
University of Exeter, United Kingdom | |
School of Agricultural, Computational and Environmental Sciences | |
University of Dublin, Ireland | |
Montpellier Universe and Particles Laboratory, France | |
Georg August University of Gottingen, Germany | |
Institution of Origin | University of Southern Queensland |
https://research.usq.edu.au/item/q514x/direct-evidence-of-a-full-dipole-flip-during-the-magnetic-cycle-of-a-sun-like-star
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