The hot Jupiter and magnetic activity of V830 Tau
PUBLISHED We report results of an extended spectropolarimetric and ph otometric monitoring of the weak- line T Tauri star V830 Tau and its recently-detected newborn close-in giant planet. Our obser- vations, carried out within the MaTYSSE programme, were spr ead over 91 d, and involved the ESPaDOnS...
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| Format: | Article in Journal/Newspaper |
| Language: | unknown |
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2017
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| Online Access: | http://hdl.handle.net/2262/79159 http://people.tcd.ie/vidottoa https://arxiv.org/pdf/1611.02055.pdf |
| Summary: | PUBLISHED We report results of an extended spectropolarimetric and ph otometric monitoring of the weak- line T Tauri star V830 Tau and its recently-detected newborn close-in giant planet. Our obser- vations, carried out within the MaTYSSE programme, were spr ead 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 Ze eman-Doppler Imaging, we characterize the surface brightness distributions, magne tic topologies and surface di ff erential rotation of V830 Tau at the time of our observations, and demo nstrate that both distributions evolve with time beyond what is expected from di ff erential rotation. We also report that near the end of our observations, V830 Tau triggered one major flar e and two weaker precursors, showing up as enhanced red-shifted emission in multiple spe ctral activity proxies. With 3 di ff erent 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 th e 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 mod elling not only the activity jitter, but also its temporal evolution over the course of our observati ons, and succeeds at reproducing our RV data down to a 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 Ta uri stars. This paper is based on observations obtained at the CFHT (ope rated by the National Research Council of Canada / CNRC, the Institut National des Sciences de l?Univers / INSU of the Centre National de la Recherche Scientifique / CNRS of France and the University of Hawaii), at the TBL (operated by Observatoire Midi-Pyr?n ?es and by INSU / CNRS), and at the Gemini Observatory (operated by the Association of Universities for Research in Astronom y, Inc., under a cooperative agreement with the National Science Fou nda- tion / NSF of the United States of America on behalf of the Gemini partnership: the NSF, the CNRC, CONICYT of Chile, Ministeri o de Ciencia, Tecnolog?a e Innovaci?n Productiva of Argentin a, and Minist?rio da Ci?ncia, Tecnologia e Inova??o of Brazil). Th is re- search also uses data obtained through the Telescope Access Pro- gram (TAP), which has been funded by the National Astronomi- cal Observatories of China, the Chinese Academy of Sciences (the Strategic Priority Research Program ?The Emergence of Cosm o- logical Structures? Grant #XDB09000000), and the Special F und for Astronomy from the Ministry of Finance. We thank the QSO teams of CFHT, TBL and Gemini for their great work and e ff orts at collecting the high-quality MaTYSSE data presented here, without which this study would not have been possible. MaTYSSE is an international collaborative resea rch pro- gramme involving experts from more than 10 di ff erent countries. We also warmly thank the IDEX initiative at Universit? F?d?rale Toulouse Midi-Pyr?n?es (UFTMiP) for funding the STEPS collaboration program between IRAP / OMP and ESO and for allocating a ?Chaire d?Attractivit?? to GAJH allowing h er reg- ularly visiting Toulouse to work on MaTYSSE data. We acknowl - edge funding from the LabEx OSUG@2020 that allowed purchas- ing the ProLine PL230 CCD imaging system installed on the 1.2 5- m telescope at CrAO. SGG acknowledges support from the Scien ce & Technology Facilities Council (STFC) via an Ernest Ruther ford Fellowship [ST / J003255 / 1]. SHPA acknowledges financial support from CNPq, CAPES and Fapemig. We finally thank the referee, Teruyuki Hirano, for his valuab le comments that helped us improve the paper |
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