Time evolution of magnetic activity cycles in young suns: The curious case of κ Ceti
- Autor(en)
- S. Boro Saikia, T. Lüftinger, C. P. Folsom, A. Antonova, E. Alecian, J. -F. Donati, M. Güdel, J. C. Hall, S. V. Jeffers, O. Kochukhov, S. C. Marsden, Y. T. Metodieva, M. Mittag, J. Morin, V. Perdelwitz, P. Petit, M. Schmid, A. A. Vidotto
- Abstrakt
Context. A detailed investigation of the magnetic properties of young Sun-like stars can provide valuable information on our Sun's magnetic past and its impact on the early Earth.
Aims: We determine the properties of the moderately rotating young Sun-like star κ Ceti's magnetic and activity cycles using 50 yr of chromospheric activity data and six epochs of spectropolarimetric observations.
Methods: The chromospheric activity was determined by measuring the flux in the Ca II H and K lines. A generalised Lomb-Scargle periodogram and a wavelet decomposition were used on the chromospheric activity data to establish the associated periodicities. The vector magnetic field of the star was reconstructed using the technique of Zeeman Doppler imaging on the spectropolarimetric observations.
Results: Our period analysis algorithms detect a 3.1 yr chromospheric cycle in addition to the star's well-known ~6 yr cycle period. Although the two cycle periods have an approximate 1:2 ratio, they exhibit an unusual temporal evolution. Additionally, the spectropolarimetric data analysis shows polarity reversals of the star's large-scale magnetic field, suggesting a ~10 yr magnetic or Hale cycle.
Conclusions: The unusual evolution of the star's chromospheric cycles and their lack of a direct correlation with the magnetic cycle establishes κ Ceti as a curious young Sun. Such complex evolution of magnetic activity could be synonymous with moderately active young Suns, which is an evolutionary path that our own Sun could have taken.- Organisation(en)
- Institut für Astrophysik
- Externe Organisation(en)
- Universität Wien, European Space Agency (ESA), Royal Military College of Canada, University of Tartu, Bulgarian Academy of Sciences (BAS), Université Grenoble-Alpes, Université de Toulouse, Institut de Recherche en Astrophysique et Planétologie (IRAP), Lowell Observatory, Max-Planck-Institut für Sonnensystemforschung, Uppsala University, University of Southern Queensland, Universität Hamburg, Université de Montpellier, Ariel University, Trinity College Dublin, Leiden University
- Journal
- Astronomy and Astrophysics
- Band
- 658
- Anzahl der Seiten
- 12
- ISSN
- 0004-6361
- DOI
- https://doi.org/10.1051/0004-6361/202141525
- Publikationsdatum
- 02-2022
- Peer-reviewed
- Ja
- ÖFOS 2012
- 103003 Astronomie, 103004 Astrophysik
- Schlagwörter
- ASJC Scopus Sachgebiete
- Astronomy and Astrophysics, Space and Planetary Science
- Link zum Portal
- https://ucrisportal.univie.ac.at/de/publications/5ad90bc7-c0ff-4532-8079-7736f7305def