The rotationally modulated polarization of ξ Boo A
Article
Article Title | The rotationally modulated polarization of ξ Boo A |
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ERA Journal ID | 1074 |
Article Category | Article |
Authors | Cotton, Daniel V. (Author), Evensberget, Dag (Author), Marsden, Stephen C. (Author), Bailey, Jeremy (Author), Zhao, Jinglin (Author), Kedziora-Chudczer, Lucyna (Author), Carter, Bradley D. (Author), Bott, Kimberly (Author), Vidotto, Aline A. (Author), Petit, Pascal (Author), Morin, Julien (Author) and Jeffers, Sandra V. (Author) |
Journal Title | Monthly Notices of the Royal Astronomical Society |
Journal Citation | 483 (2), pp. 1574-1581 |
Number of Pages | 8 |
Year | 2019 |
Publisher | Oxford University Press |
Place of Publication | United Kingdom |
ISSN | 0035-8711 |
1365-2966 | |
Digital Object Identifier (DOI) | https://doi.org/10.1093/mnras/sty3180 |
Web Address (URL) | https://academic.oup.com/mnras/article/483/2/1574/5218518 |
Abstract | We have observed the active star ξ Boo A (HD 131156A) with high precision broadband linear polarimetry contemporaneously with circular spectropolarimetry. We find both signals aremodulated by the 6.43 d rotation period of ξ BooA. The signals from the two techniques are 0.25 out of phase, consistent with the broadband linear polarization resulting from differential saturation of spectral lines in the global transverse magnetic field. The mean magnitude of the linear polarization signal is ∼4 ppmG-1 but its structure is complex and the amplitude of the variations suppressed relative to the longitudinal magnetic field. The result has important implications for current attempts to detect polarized light from hot Jupiters orbiting active stars in the combined light of the star and planet. In such work stellar activity will manifest as noise, both on the time-scale of stellar rotation, and on longer time-scales - where changes in activity level will manifest as a baseline shift between observing runs. |
Keywords | Polarization; Stars: activity; Stars: individual HD 131156A; Stars: magnetic field |
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 © 2019 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved. |
Byline Affiliations | University of New South Wales |
Centre for Astrophysics | |
University of New South Wales | |
University of Washington, United States | |
University of Dublin, Ireland | |
University of Toulouse, France | |
University of Montpellier, France | |
University of Gottingen, Germany | |
Institution of Origin | University of Southern Queensland |
Funder | Australian Research Council |
https://research.usq.edu.au/item/q5720/the-rotationally-modulated-polarization-of-boo-a
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