The hot Jupiter of the magnetically active weak-line T Tauri star V830 Tau

• Published in: Monthly Notices of the Royal Astronomical Society
• Main Authors: Donati, J-F., Yu, L., Moutou, C., Cameron, A. C., Malo, L., Grankin, K., Hebrard, E., Hussain, G. A. J., Vidotto, A. A., Alencar, S. H. P., Haywood, R. D., Bouvier, J., Petit, P., Takami, M., Herczeg, G. J., Gregory, S. G., Jardine, M. M., Morin, J.
• Other Authors: Donati, JF (reprint author), Univ Toulouse, UPS OMP, IRAP, 14 Ave E Belin, F-31400 Toulouse, France.; Donati, JF (reprint author), CNRS, IRAP UMR 5277, 14 Ave E Belin, F-31400 Toulouse, France., Univ Toulouse, UPS OMP, IRAP, 14 Ave E Belin, F-31400 Toulouse, France., CNRS, IRAP UMR 5277, 14 Ave E Belin, F-31400 Toulouse, France., CFHT Corp, 65-1238 Mamalahoa Hwy, Kamuela, HI 96743 USA., Univ St Andrews, Sch Phys & Astron, SUPA, St Andrews KY16 9SS, Fife, Scotland., Univ Montreal, Dept Phys, CP 6128,Succursale Ctr Ville, Montreal, PQ H3C 3J7, Canada., Crimean Astrophys Observ, Nauchny 298409, Crimea, Russia., York Univ, Dept Phys & Astron, Toronto, ON L3T 3R1, Canada., ESO, Karl Schwarzschild Str 2, D-85748 Garching, Germany., Univ Dublin, Trinity Coll Dublin, Sch Phys, Dublin 2, Ireland., Univ Fed Minas Gerais, ICEx, Dept Fis, Ave Antonio Carlos 6627, BR-30270901 Belo Horizonte, MG, Brazil., Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA., Univ Grenoble Alpes, IPAG, BP 53, F-38041 Grenoble 09, France., CNRS, IPAG UMR 5274, BP 53, F-38041 Grenoble 09, France., Acad Sinica, Inst Astron & Astrophys, POB 23-141, Taipei 106, Taiwan., Peking Univ, Kavli Inst Astron & Astrophys, Yi He Yuan Lu 5, Beijing 100871, Peoples R China., Univ Montpellier, CNRS, LUPM, Pl E Bataillon, F-34095 Montpellier, France., Donati, JF (reprint author), CNRS, IRAP UMR 5277, 14 Ave E Belin, F-31400 Toulouse, France.
• Format: Journal/Newspaper
• Language: English
• Published: MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 2017
• Subjects: techniques: polarimetric; stars: formation; stars: imaging; stars: individual:V830 Tau; stars: magnetic field; planetary systems; MAIN-SEQUENCE STAR; MAGNETOSPHERIC ACCRETION; YOUNG SUNS; SPECTROPOLARIMETRIC OBSERVATIONS; PHOTOMETRIC VARIABILITY; DIFFERENTIAL ROTATION; GIANT PLANETS; FIELDS; TOPOLOGIES; EVOLUTION; Canada; Gemini; Jupiter; narval
• Online Access: https://hdl.handle.net/20.500.11897/474901; https://doi.org/10.1093/mnras/stw2904

We report results of an extended spectropolarimetric and photometric monitoring of the weakline T Tauri star V830 Tau and its recently detected newborn close-in giant planet. Our observations, carried out within the MaTYSSE (Magnetic Topologies of Young Stars and the Survival of close-in giant Exoplanets) programme, were spread over 91 d, and involved the ESPaDOnS and Narval spectropolarimeters linked to the 3.6-m Canada-France-Hawaii, the 2-m Bernard Lyot, and the 8-m Gemini-North Telescopes. Using Zeeman-Doppler Imaging, we characterize the surface brightness distributions, magnetic topologies, and surface differential rotation of V830 Tau at the time of our observations, and demonstrate that both distributions evolve with time beyond what is expected from differential rotation. We also report that near the end of our observations, V830 Tau triggered one major flare and two weaker precursors, showing up as enhanced redshifted emission in multiple spectral activity proxies. With three different filtering techniques, we model the radial velocity (RV) activity jitter (of semi-amplitude 1.2 km s(-1)) that V830 Tau generates, successfully retrieve the 68 +/- 11 m s(-1) RV planet signal hiding behind the jitter, further confirm the existence of V830 Tau b, and better characterize its orbital parameters. We find that the method based on Gaussian-process regression performs best thanks to its higher ability at modelling not only the activity jitter, but also its temporal evolution over the course of our observations, and succeeds at reproducing our RV data down to an rms precision of 35 m s(-1) . Our result provides new observational constraints on scenarios of star/planet formation and demonstrates the scientific potential of large-scale searches for close-in giant planets around T Tauri stars. National Astronomical Observatories of China; Chinese Academy of Sciences [XDB09000000]; Special Fund for Astronomy from the Ministry of Finance; IDEX initiative at Universite Federale Toulouse Midi-Pyrenees (UFTMiP); LabEx OSUG@2020; Science & Technology Facilities Council (STFC) via an Ernest Rutherford Fellowship [ST/J003255/1]; CNPq; CAPES; Fapemig SCI(E) ARTICLE 3 3343-3360 465