Eridani: an active K dwarf and a planet hosting star? The variability of its large-scale magnetic field topology
Article
Article Title | Eridani: an active K dwarf and a planet hosting star? The variability of its large-scale magnetic field topology |
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ERA Journal ID | 1050 |
Article Category | Article |
Authors | Jeffers, S. V. (Author), Petit, P. (Author), Marsden, S. C. (Author), Morin, J. (Author), Donati, J. -F. (Author) and Folsom, C. P. (Author) |
Journal Title | Astronomy and Astrophysics: a European journal |
Journal Citation | 569, pp. 1-8 |
Number of Pages | 8 |
Year | 2014 |
Publisher | EDP Sciences |
Place of Publication | Les Ulis, France |
ISSN | 0004-6361 |
1432-0746 | |
Digital Object Identifier (DOI) | https://doi.org/10.1051/0004-6361/201423725 |
Abstract | The young K-dwarf Eridani is an example of a young active planet hosting star that has shown over long-term monitoring of its chromospheric emission to exhibit cyclic magnetic activity. In this paper, we investigate how Eridani's large-scale magnetic field geometry evolves over the timescale of its S-index cycle using spectropolarimetric observations and the technique of Zeeman-Doppler imaging. Our observations comprise six epochs secured over a time period of nearly seven years, with each almost yearly observational epoch showing a dramatic change in the large-scale magnetic field topology, with no stable regions. The poloidal field varies from strongly dipolar to mono-polar and the toroidal field is non-existent to begin with and then emerges to dominate the magnetic field energy before disappearing and re-emerging again. A potential cycle is detected in the poloidal field, but further observations are needed to confirm this. |
Keywords | magnetic fields; star activity; starspots |
ANZSRC Field of Research 2020 | 510109. Stellar astronomy and planetary systems |
519999. Other physical sciences not elsewhere classified | |
510903. Mesospheric, thermospheric, ionospheric and magnetospheric physics | |
Public Notes | © The European Southern Observatory (ESO) 2014. This publication is copyright. It may be reproduced in whole or in part for the purposes of study, research, or review, but is subject to the inclusion of an acknowledgment of the source. |
Byline Affiliations | Georg August University of Gottingen, Germany |
University of Toulouse, France | |
Computational Engineering and Science Research Centre | |
University of Montpellier, France | |
Institution of Origin | University of Southern Queensland |
https://research.usq.edu.au/item/q2w92/eridani-an-active-k-dwarf-and-a-planet-hosting-star-the-variability-of-its-large-scale-magnetic-field-topology
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