Magnetospheric accretion on the T Tauri star BP Tauri
MNRAS, in press From observations collected with the ESPaDOnS and NARVAL spectropolarimeters, we report the detection of Zeeman signatures on the classical T Tauri star BP Tau. Circular polarisation signatures in photospheric lines and in narrow emission lines tracing magnetospheric accretion are mo...
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ftunivlyon:oai:HAL:hal-00256232v1 2023-05-15T18:50:49+02:00 Magnetospheric accretion on the T Tauri star BP Tauri Donati, J. F. Jardine, M. M. Gregory, S. G. Petit, P. Paletou, F. Bouvier, J. Dougados, C. Menard, F. Cameron, A. C. Harries, T. J. Hussain, G. A. J. Unruh, Y. Morin, J. Marsden, S. C. Manset, N. Auriere, M. Catala, C. Alecian, E. Laboratoire d'Astrophysique de Toulouse-Tarbes École normale supérieure - Lyon (ENS Lyon)-Université Toulouse III - Paul Sabatier (UT3) Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées University of St Andrews Scotland Laboratoire d'Astrophysique de Grenoble (LAOG) Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS) School of Physics (EXETER) University of Exeter Canada-France-Hawaii Telescope Corporation (CFHT) National Research Council of Canada (NRC)-Centre National de la Recherche Scientifique (CNRS)-University of Hawai'i Honolulu (UH) Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA) Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS) 2008-02-14 https://hal.archives-ouvertes.fr/hal-00256232 en eng HAL CCSD info:eu-repo/semantics/altIdentifier/arxiv/0802.2052 hal-00256232 https://hal.archives-ouvertes.fr/hal-00256232 ARXIV: 0802.2052 https://hal.archives-ouvertes.fr/hal-00256232 2008 [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO] info:eu-repo/semantics/preprint Preprints, Working Papers, . 2008 ftunivlyon 2022-08-19T00:36:25Z MNRAS, in press From observations collected with the ESPaDOnS and NARVAL spectropolarimeters, we report the detection of Zeeman signatures on the classical T Tauri star BP Tau. Circular polarisation signatures in photospheric lines and in narrow emission lines tracing magnetospheric accretion are monitored throughout most of the rotation cycle of BP Tau at two different epochs in 2006. We observe that rotational modulation dominates the temporal variations of both unpolarised and circularly polarised spectral proxies tracing the photosphere and the footpoints of accretion funnels. From the complete data sets at each epoch, we reconstruct the large-scale magnetic topology and the location of accretion spots at the surface of BP Tau using tomographic imaging. We find that the field of BP Tau involves a 1.2 kG dipole and 1.6 kG octupole, both slightly tilted with respect to the rotation axis. Accretion spots coincide with the two main magnetic poles at high latitudes and overlap with dark photospheric spots; they cover about 2% of the stellar surface. The strong mainly-axisymmetric poloidal field of BP Tau is very reminiscent of magnetic topologies of fully-convective dwarfs. It suggests that magnetic fields of fully-convective cTTSs such as BP Tau are likely not fossil remants, but rather result from vigorous dynamo action operating within the bulk of their convective zones. Preliminary modelling suggests that the magnetosphere of BP Tau extends to distances of at least 4 R* to ensure that accretion spots are located at high latitudes, and is not blown open close to the surface by a putative stellar wind. It apparently succeeds in coupling to the accretion disc as far out as the corotation radius, and could possibly explain the slow rotation of BP Tau. Report narval narval Université de Lyon: HAL |
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Université de Lyon: HAL |
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ftunivlyon |
language |
English |
topic |
[PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO] |
spellingShingle |
[PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO] Donati, J. F. Jardine, M. M. Gregory, S. G. Petit, P. Paletou, F. Bouvier, J. Dougados, C. Menard, F. Cameron, A. C. Harries, T. J. Hussain, G. A. J. Unruh, Y. Morin, J. Marsden, S. C. Manset, N. Auriere, M. Catala, C. Alecian, E. Magnetospheric accretion on the T Tauri star BP Tauri |
topic_facet |
[PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO] |
description |
MNRAS, in press From observations collected with the ESPaDOnS and NARVAL spectropolarimeters, we report the detection of Zeeman signatures on the classical T Tauri star BP Tau. Circular polarisation signatures in photospheric lines and in narrow emission lines tracing magnetospheric accretion are monitored throughout most of the rotation cycle of BP Tau at two different epochs in 2006. We observe that rotational modulation dominates the temporal variations of both unpolarised and circularly polarised spectral proxies tracing the photosphere and the footpoints of accretion funnels. From the complete data sets at each epoch, we reconstruct the large-scale magnetic topology and the location of accretion spots at the surface of BP Tau using tomographic imaging. We find that the field of BP Tau involves a 1.2 kG dipole and 1.6 kG octupole, both slightly tilted with respect to the rotation axis. Accretion spots coincide with the two main magnetic poles at high latitudes and overlap with dark photospheric spots; they cover about 2% of the stellar surface. The strong mainly-axisymmetric poloidal field of BP Tau is very reminiscent of magnetic topologies of fully-convective dwarfs. It suggests that magnetic fields of fully-convective cTTSs such as BP Tau are likely not fossil remants, but rather result from vigorous dynamo action operating within the bulk of their convective zones. Preliminary modelling suggests that the magnetosphere of BP Tau extends to distances of at least 4 R* to ensure that accretion spots are located at high latitudes, and is not blown open close to the surface by a putative stellar wind. It apparently succeeds in coupling to the accretion disc as far out as the corotation radius, and could possibly explain the slow rotation of BP Tau. |
author2 |
Laboratoire d'Astrophysique de Toulouse-Tarbes École normale supérieure - Lyon (ENS Lyon)-Université Toulouse III - Paul Sabatier (UT3) Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées University of St Andrews Scotland Laboratoire d'Astrophysique de Grenoble (LAOG) Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS) School of Physics (EXETER) University of Exeter Canada-France-Hawaii Telescope Corporation (CFHT) National Research Council of Canada (NRC)-Centre National de la Recherche Scientifique (CNRS)-University of Hawai'i Honolulu (UH) Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA) Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS) |
format |
Report |
author |
Donati, J. F. Jardine, M. M. Gregory, S. G. Petit, P. Paletou, F. Bouvier, J. Dougados, C. Menard, F. Cameron, A. C. Harries, T. J. Hussain, G. A. J. Unruh, Y. Morin, J. Marsden, S. C. Manset, N. Auriere, M. Catala, C. Alecian, E. |
author_facet |
Donati, J. F. Jardine, M. M. Gregory, S. G. Petit, P. Paletou, F. Bouvier, J. Dougados, C. Menard, F. Cameron, A. C. Harries, T. J. Hussain, G. A. J. Unruh, Y. Morin, J. Marsden, S. C. Manset, N. Auriere, M. Catala, C. Alecian, E. |
author_sort |
Donati, J. F. |
title |
Magnetospheric accretion on the T Tauri star BP Tauri |
title_short |
Magnetospheric accretion on the T Tauri star BP Tauri |
title_full |
Magnetospheric accretion on the T Tauri star BP Tauri |
title_fullStr |
Magnetospheric accretion on the T Tauri star BP Tauri |
title_full_unstemmed |
Magnetospheric accretion on the T Tauri star BP Tauri |
title_sort |
magnetospheric accretion on the t tauri star bp tauri |
publisher |
HAL CCSD |
publishDate |
2008 |
url |
https://hal.archives-ouvertes.fr/hal-00256232 |
genre |
narval narval |
genre_facet |
narval narval |
op_source |
https://hal.archives-ouvertes.fr/hal-00256232 2008 |
op_relation |
info:eu-repo/semantics/altIdentifier/arxiv/0802.2052 hal-00256232 https://hal.archives-ouvertes.fr/hal-00256232 ARXIV: 0802.2052 |
_version_ |
1766244579256827904 |