TY - JOUR
T1 - Magnetic activity and hot Jupiters of young Suns
T2 - The weak-line T Tauri stars V819 Tau and V830 Tau
AU - MaTYSSE Collaboration
AU - Donati, J. F.
AU - Hébrard, E.
AU - Hussain, G. A.J.
AU - Moutou, C.
AU - Malo, L.
AU - Grankin, K.
AU - Vidotto, A. A.
AU - Alencar, S. H.P.
AU - Gregory, S. G.
AU - Jardine, M. M.
AU - Herczeg, G.
AU - Morin, J.
AU - Fares, R.
AU - Ménard, F.
AU - Bouvier, J.
AU - Delfosse, X.
AU - Doyon, R.
AU - Takami, M.
AU - Figueira, P.
AU - Petit, P.
AU - Boisse, I.
N1 - Funding Information:
This paper is based on observations obtained at the CFHT, operated by the National Research Council of Canada, the Institut National des Sciences de l'Univers of the Centre National de la Recherche Scientifique (INSU/CNRS) of France and the University of Hawaii. We thank the CFHT QSO team for its great work and effort at collecting the high-quality MaTYSSE data presented in this paper. MaTYSSE is an international collaborative research programme involving experts from more than 10 different countries (France, Canada, Brazil, Taiwan, UK, Russia, Chile, USA, Switzerland, Portugal, China and Italy). We also warmly thank the IDEX initiative at Université Fédérale ToulouseMidi-Pyrénées (UFTMiP) for funding the STEPS collaboration program between IRAP/OMP andESOand for allocating a 'Chaire d'Attractivité' to GAJH, allowing her to regularly visit Toulouse to work on MaTYSSE data. We acknowledge funding from the LabEx OSUG@2020 that allowed purchasing the ProLine PL230 CCD imaging system installed on the 1.25-m telescope at CrAO. SGG acknowledges support from the Science & Technology Facilities Council (STFC) via an Ernest Rutherford Fellowship [ST/J003255/1]. SHPAacknowledges financial support from CNPq, CAPES and Fapemig. AAV acknowledges support from the Swiss National Science Foundation (SNSF) via the allocation of an Ambizione Followship.
Publisher Copyright:
© 2015 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society.
PY - 2015/11/11
Y1 - 2015/11/11
N2 - We report results of a spectropolarimetric and photometricmonitoring of the weak-line T Tauri stars (wTTSs) V819 Tau and V830 Tau within theMaTYSSE (Magnetic Topologies of Young Stars and the Survival of close-in giant Exoplanets) programme, involving the ESPaDOnS spectropolarimeter at the Canada-France-Hawaii Telescope. At ≃ 3 Myr, both stars dissipated their discs recently and are interesting objects for probing star and planet formation. Profile distortions and Zeeman signatures are detected in the unpolarized and circularly polarized lines, whose rotational modulation we modelled using tomographic imaging, yielding brightness and magnetic maps for both stars. We find that the large-scale magnetic fields of V819 Tau and V830 Tau are mostly poloidal and can be approximated at large radii by 350-400 G dipoles tilted at ≃ 30° to the rotation axis. They are significantly weaker than the field of GQ Lup, an accreting classical T Tauri star (cTTS) with similar mass and age which can be used to compare the magnetic properties of wTTSs and cTTSs. The reconstructed brightness maps of both stars include cool spots and warm plages. Surface differential rotation is small, typically ≃ 4.4 times smaller than on the Sun, in agreement with previous results on wTTSs. Using our Doppler images to model the activity jitter and filter it out from the radial velocity (RV) curves, we obtain RV residuals with dispersions of 0.033 and 0.104 km s-1 for V819 Tau and V830 Tau, respectively. RV residuals suggest that a hot Jupiter may be orbiting V830 Tau, though additional data are needed to confirm this preliminary result.We find no evidence for close-in giant planet around V819 Tau.
AB - We report results of a spectropolarimetric and photometricmonitoring of the weak-line T Tauri stars (wTTSs) V819 Tau and V830 Tau within theMaTYSSE (Magnetic Topologies of Young Stars and the Survival of close-in giant Exoplanets) programme, involving the ESPaDOnS spectropolarimeter at the Canada-France-Hawaii Telescope. At ≃ 3 Myr, both stars dissipated their discs recently and are interesting objects for probing star and planet formation. Profile distortions and Zeeman signatures are detected in the unpolarized and circularly polarized lines, whose rotational modulation we modelled using tomographic imaging, yielding brightness and magnetic maps for both stars. We find that the large-scale magnetic fields of V819 Tau and V830 Tau are mostly poloidal and can be approximated at large radii by 350-400 G dipoles tilted at ≃ 30° to the rotation axis. They are significantly weaker than the field of GQ Lup, an accreting classical T Tauri star (cTTS) with similar mass and age which can be used to compare the magnetic properties of wTTSs and cTTSs. The reconstructed brightness maps of both stars include cool spots and warm plages. Surface differential rotation is small, typically ≃ 4.4 times smaller than on the Sun, in agreement with previous results on wTTSs. Using our Doppler images to model the activity jitter and filter it out from the radial velocity (RV) curves, we obtain RV residuals with dispersions of 0.033 and 0.104 km s-1 for V819 Tau and V830 Tau, respectively. RV residuals suggest that a hot Jupiter may be orbiting V830 Tau, though additional data are needed to confirm this preliminary result.We find no evidence for close-in giant planet around V819 Tau.
KW - Stars: formation
KW - Stars: imaging
KW - Stars: individual: V819 Tau
KW - Stars: individual: V830 Tau
KW - Stars: magnetic fields
KW - Techniques: polarimetric
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U2 - 10.1093/mnras/stv1837
DO - 10.1093/mnras/stv1837
M3 - Article
AN - SCOPUS:84992043759
VL - 453
SP - 3706
EP - 3719
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
SN - 0035-8711
IS - 4
ER -