%0 Journal Article
%T The rotationally modulated polarization of ξ Boo A
%+ Australian Centre for Astrobiology
%+ University of Southern Queensland (USQ)
%+ School of Physics [UNSW Sydney] (UNSW)
%+ University of Washington [Seattle]
%+ Trinity College Dublin
%+ Institut de recherche en astrophysique et planétologie (IRAP)
%+ Laboratoire Univers et Particules de Montpellier (LUPM)
%+ Institut für Astrophysik [Göttingen]
%A Cotton, Daniel
%A Evensberget, Dag
%A Marsden, Stephen, C.
%A Bailey, Jeremy
%A Zhao, Jinglin
%A Kedziora-Chudczer, Lucyna
%A Carter, Bradley
%A Bott, Kimberly
%A Vidotto, Aline, A.
%A Petit, Pascal
%A Morin, Julien
%A Jeffers, Sandra, V.
%< avec comité de lecture
%@ 0035-8711
%J Monthly Notices of the Royal Astronomical Society
%I Oxford University Press (OUP): Policy P - Oxford Open Option A
%V 483
%N 2
%P 1574-1581
%8 2019-02-21
%D 2019
%Z 1811.08534
%R 10.1093/mnras/sty3180
%Z Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR]Journal articles
%X We have observed the active starξBoo A (HD 131156A) with high precision broadbandlinear polarimetry contemporaneously with circular spectropolarimetry. We find both signalsare modulated by the 6.43 d rotation period ofξBoo A. The signals from the two techniques are0.25 out of phase, consistent with the broadband linear polarization resulting from differentialsaturation of spectral lines in the global transverse magnetic field. The mean magnitude ofthe linear polarization signal is∼4 ppm G–1but its structure is complex and the amplitude ofthe variations suppressed relative to the longitudinal magnetic field. The result has importantimplications for current attempts to detect polarized light from hot Jupiters orbiting activestars in the combined light of the star and planet. In such work stellar activity will manifest asnoise, both on the time-scale of stellar rotation, and on longer time-scales – where changes inactivity level will manifest as a baseline shift between observing runs
%G English
%2 https://hal.science/hal-01962834/document
%2 https://hal.science/hal-01962834/file/sty3180.pdf
%L hal-01962834
%U https://hal.science/hal-01962834
%~ IN2P3
%~ IRD
%~ INSU
%~ METEO
%~ UNIV-TLSE3
%~ CNRS
%~ CNES
%~ OMP
%~ OMP-IRAP
%~ LUPM
%~ UNIV-MONTPELLIER
%~ LUPM_AS
%~ UNIV-UT3
%~ UT3-INP
%~ UT3-TOULOUSEINP
%~ UM-2015-2021