The relation between stellar magnetic field geometry and chromospheric activity cycles – II The rapid 120-day magnetic cycle of τ Bootis
Article
Article Title | The relation between stellar magnetic field geometry and chromospheric activity cycles – II The rapid 120-day magnetic cycle of τ Bootis |
---|---|
ERA Journal ID | 1074 |
Article Category | Article |
Authors | Jeffers, S. V. (Author), Mengel, M. (Author), Moutou, C. (Author), Marsden, S. C. (Author), Barnes, J. R. (Author), Jardine, M. M. (Author), Petit, P. (Author), Schmitt, J. H. M. M. (Author), See, V. (Author) and Vidotto, A. A. (Author) |
Journal Title | Monthly Notices of the Royal Astronomical Society |
Journal Citation | 479 (4), pp. 5266-5271 |
Number of Pages | 6 |
Year | 2018 |
Publisher | Oxford University Press |
Place of Publication | United Kingdom |
ISSN | 0035-8711 |
1365-2966 | |
Digital Object Identifier (DOI) | https://doi.org/10.1093/mnras/sty1717 |
Web Address (URL) | https://academic.oup.com/mnras/article/479/4/5266/5049306 |
Abstract | One of the aims of the BCool programme is to search for cycles in other stars and to understand how similar they are to the Sun. In this paper, we aim to monitor the evolution of τ Boo’s large-scalemagnetic field using high-cadence observations covering its chromospheric activity maximum. For the first time, we detect a polarity switch that is in phase with τ Boo’s 120-day chromospheric activity maximum and its inferred X-ray activity cycle maximum. This means that τ Boo has a very fast magnetic cycle of only 240 days. At activity maximum τ Boo’s large-scale field geometry is very similar to the Sun at activity maximum: it is complex and there is a weak dipolar component. In contrast, we also see the emergence of a strong toroidal component which has not been observed on the Sun, and a potentially overlapping butterfly pattern where the next cycle begins before the previous one has finished. |
Keywords | polarimetric technique; τ Boo; magneticfield; solar-type; starspots |
ANZSRC Field of Research 2020 | 510109. Stellar astronomy and planetary systems |
Public Notes | This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society ©: 2018 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved. |
Byline Affiliations | Georg August University of Gottingen, Germany |
Computational Engineering and Science Research Centre | |
Canada-France-Hawaii Telescope, United States | |
Open University, United Kingdom | |
University of St Andrews, United Kingdom | |
French National Centre for Scientific Research, France | |
University of Hamburg, Germany | |
University of Exeter, United Kingdom | |
University of Dublin, Ireland | |
Institution of Origin | University of Southern Queensland |
https://research.usq.edu.au/item/q514v/the-relation-between-stellar-magnetic-field-geometry-and-chromospheric-activity-cycles-ii-the-rapid-120-day-magnetic-cycle-of-bootis
Download files
198
total views90
total downloads22
views this month4
downloads this month