Star-disk interactions in the strongly accreting T Tauri star S CrA N

Context. Classical T Tauri stars are thought to accrete material from their surrounding protoplanetary disks through funnel flows along their magnetic field lines. The classical T Tauri stars with high accretion rates (∼10−7 M⊙ yr−1) are ideal targets for testing this magnetospheric accretion scenar...

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Detalles Bibliográficos
Autores: Hugo Nowacki, Evelyne Alecian, Karine Perraut, Bonnie Zaire, Colin Folsom, Kim Pouilly, Jerome Bouvier, Rajeev Manick, George Pantolmos, Alana Sousa, Catherine Dougados, Gaitee Hussain, Silvia Helena Paixao Alencar, Jean-Baptiste Le Bouquin
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2023
País:Brasil
Institución:Universidade Federal de Minas Gerais (UFMG)
Repositorio:Repositório Institucional da UFMG
Idioma:inglés
OAI Identifier:oai:repositorio.ufmg.br:1843/79457
Acceso en línea:https://doi.org/10.1051/0004-6361/202347145
http://hdl.handle.net/1843/79457
https://orcid.org/0000-0002-5762-0249
https://orcid.org/0000-0001-5260-7179
https://orcid.org/0000-0003-3099-757X
https://orcid.org/0000-0002-9328-9530
https://orcid.org/0000-0002-9023-7890
https://orcid.org/0000-0002-9628-2959
https://orcid.org/0000-0002-7450-6712
https://orcid.org/0000-0001-7633-7038
https://orcid.org/0000-0001-7788-3727
https://orcid.org/0000-0001-7397-8972
https://orcid.org/0000-0001-6660-936X
https://orcid.org/0000-0003-3547-3783
https://orcid.org/0000-0002-0493-4674
Access Level:acceso abierto
Palabra clave:Stars: variables: T Tauri
Stars: individual: S CrA N
Herbig Ae/Be
Stars: magnetic field
Techniques: spectroscopic
Techniques: polarimetric
Accretion
Accretion disks
Estrelas - Campos magnéticos
Estrelas T Tauri
Astronomia
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oai_identifier_str oai:repositorio.ufmg.br:1843/79457
network_acronym_str BR
network_name_str Brasil
repository_id_str
dc.title.none.fl_str_mv Star-disk interactions in the strongly accreting T Tauri star S CrA N
title Star-disk interactions in the strongly accreting T Tauri star S CrA N
spellingShingle Star-disk interactions in the strongly accreting T Tauri star S CrA N
Hugo Nowacki
Stars: variables: T Tauri
Stars: individual: S CrA N
Herbig Ae/Be
Stars: magnetic field
Techniques: spectroscopic
Techniques: polarimetric
Accretion
Accretion disks
Estrelas - Campos magnéticos
Estrelas T Tauri
Astronomia
title_short Star-disk interactions in the strongly accreting T Tauri star S CrA N
title_full Star-disk interactions in the strongly accreting T Tauri star S CrA N
title_fullStr Star-disk interactions in the strongly accreting T Tauri star S CrA N
title_full_unstemmed Star-disk interactions in the strongly accreting T Tauri star S CrA N
title_sort Star-disk interactions in the strongly accreting T Tauri star S CrA N
dc.creator.none.fl_str_mv Hugo Nowacki
Evelyne Alecian
Karine Perraut
Bonnie Zaire
Colin Folsom
Kim Pouilly
Jerome Bouvier
Rajeev Manick
George Pantolmos
Alana Sousa
Catherine Dougados
Jerome Bouvier
Gaitee Hussain
Silvia Helena Paixao Alencar
Jean-Baptiste Le Bouquin
author Hugo Nowacki
author_facet Hugo Nowacki
Evelyne Alecian
Karine Perraut
Bonnie Zaire
Colin Folsom
Kim Pouilly
Jerome Bouvier
Rajeev Manick
George Pantolmos
Alana Sousa
Catherine Dougados
Gaitee Hussain
Silvia Helena Paixao Alencar
Jean-Baptiste Le Bouquin
author_role author
author2 Evelyne Alecian
Karine Perraut
Bonnie Zaire
Colin Folsom
Kim Pouilly
Jerome Bouvier
Rajeev Manick
George Pantolmos
Alana Sousa
Catherine Dougados
Gaitee Hussain
Silvia Helena Paixao Alencar
Jean-Baptiste Le Bouquin
author2_role author
author
author
author
author
author
author
author
author
author
author
author
author
dc.subject.por.fl_str_mv Stars: variables: T Tauri
Stars: individual: S CrA N
Herbig Ae/Be
Stars: magnetic field
Techniques: spectroscopic
Techniques: polarimetric
Accretion
Accretion disks
Estrelas - Campos magnéticos
Estrelas T Tauri
Astronomia
topic Stars: variables: T Tauri
Stars: individual: S CrA N
Herbig Ae/Be
Stars: magnetic field
Techniques: spectroscopic
Techniques: polarimetric
Accretion
Accretion disks
Estrelas - Campos magnéticos
Estrelas T Tauri
Astronomia
description Context. Classical T Tauri stars are thought to accrete material from their surrounding protoplanetary disks through funnel flows along their magnetic field lines. The classical T Tauri stars with high accretion rates (∼10−7 M⊙ yr−1) are ideal targets for testing this magnetospheric accretion scenario in a sustained regime. Aims. We constrained the accretion-ejection phenomena around the strongly accreting northern component of the S CrA young binary system (S CrA N) by deriving its magnetic field topology and its magnetospheric properties, and by detecting ejection signatures, if any. Methods. We led a two-week observing campaign on S CrA N with the ESPaDOnS optical spectropolarimeter at the Canada-France-Hawaii Telescope. We recorded 12 Stokes I and V spectra over 14 nights. We computed the corresponding least-squares deconvolution (LSD) profiles of the photospheric lines and performed Zeeman-Doppler imaging (ZDI). We analyzed the kinematics of noticeable emission lines, namely He I λ5876 and the first four lines of the Balmer series, which are known to trace the accretion process. Results. We found that S CrA N is a low-mass (0.8 M⊙) young (∼1 Myr) and fully convective object exhibiting strong and variable veiling (with a mean value of 7 ± 2), which suggests that the star is in a strong accretion regime. These findings could indicate a stellar evolutionary stage between Class I and Class II for S CrA N. We reconstructed an axisymmetric large-scale magnetic field (∼70% of the total energy) that is primarily located in the dipolar component, but has significant higher poloidal orders. From the narrow emission component radial velocity curve of He I λ5876, we derived a stellar rotation period of P* = 7.3 ± 0.2 days. We found a magnetic truncation radius of ∼2 R* which is significantly closer to the star than the corotation radius of ∼6 R*, suggesting that S CrA N is in an unstable accretion regime. That the truncation radius is quite smaller than the size of the Brγ line emitting region, as measured with the GRAVITY interferometer (∼8 R*), supports the presence of outflows, which is nicely corroborated by the line profiles presented in this work. Conclusions. The findings from spectropolarimetry are complementary to those provided by optical long-baseline interferometry, allowing us to construct a coherent view of the innermost regions of a young, strongly accreting star. The strong and complex magnetic field reconstructed for S CrA N is inconsistent with the observed magnetic signatures of the emission lines associated with the postshock region, however. We recommend a multitechnique synchronized campaign of several days to place more constrains on a system that varies on a timescale of about one day.
publishDate 2023
dc.date.none.fl_str_mv 2023-10-10
2025-01-23T23:56:34Z
2025-01-23T23:56:34Z
dc.type.status.fl_str_mv info:eu-repo/semantics/publishedVersion
dc.type.driver.fl_str_mv info:eu-repo/semantics/article
format article
status_str publishedVersion
dc.identifier.uri.fl_str_mv https://doi.org/10.1051/0004-6361/202347145
0004-6361
http://hdl.handle.net/1843/79457
https://orcid.org/0000-0002-5762-0249
https://orcid.org/0000-0001-5260-7179
https://orcid.org/0000-0003-3099-757X
https://orcid.org/0000-0002-9328-9530
https://orcid.org/0000-0002-9023-7890
https://orcid.org/0000-0002-9023-7890
https://orcid.org/0000-0002-9628-2959
https://orcid.org/0000-0002-7450-6712
https://orcid.org/0000-0001-7633-7038
https://orcid.org/0000-0001-7788-3727
https://orcid.org/0000-0001-7397-8972
https://orcid.org/0000-0001-6660-936X
https://orcid.org/0000-0003-3547-3783
https://orcid.org/0000-0002-0493-4674
url https://doi.org/10.1051/0004-6361/202347145
http://hdl.handle.net/1843/79457
https://orcid.org/0000-0002-5762-0249
https://orcid.org/0000-0001-5260-7179
https://orcid.org/0000-0003-3099-757X
https://orcid.org/0000-0002-9328-9530
https://orcid.org/0000-0002-9023-7890
https://orcid.org/0000-0002-9628-2959
https://orcid.org/0000-0002-7450-6712
https://orcid.org/0000-0001-7633-7038
https://orcid.org/0000-0001-7788-3727
https://orcid.org/0000-0001-7397-8972
https://orcid.org/0000-0001-6660-936X
https://orcid.org/0000-0003-3547-3783
https://orcid.org/0000-0002-0493-4674
identifier_str_mv 0004-6361
dc.language.iso.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv Astronomy & astrophysics
dc.rights.driver.fl_str_mv info:eu-repo/semantics/openAccess
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv pdf
application/pdf
dc.publisher.none.fl_str_mv Universidade Federal de Minas Gerais
Brasil
ICX - DEPARTAMENTO DE FÍSICA
UFMG
publisher.none.fl_str_mv Universidade Federal de Minas Gerais
Brasil
ICX - DEPARTAMENTO DE FÍSICA
UFMG
dc.source.none.fl_str_mv reponame:Repositório Institucional da UFMG
instname:Universidade Federal de Minas Gerais (UFMG)
instacron:UFMG
instname_str Universidade Federal de Minas Gerais (UFMG)
instacron_str UFMG
institution UFMG
reponame_str Repositório Institucional da UFMG
collection Repositório Institucional da UFMG
repository.name.fl_str_mv Repositório Institucional da UFMG - Universidade Federal de Minas Gerais (UFMG)
repository.mail.fl_str_mv repositorio@ufmg.br
_version_ 1853663266966863872
spelling Star-disk interactions in the strongly accreting T Tauri star S CrA NStars: variables: T TauriStars: individual: S CrA NHerbig Ae/BeStars: magnetic fieldTechniques: spectroscopicTechniques: polarimetricAccretionAccretion disksEstrelas - Campos magnéticosEstrelas T TauriAstronomiaContext. Classical T Tauri stars are thought to accrete material from their surrounding protoplanetary disks through funnel flows along their magnetic field lines. The classical T Tauri stars with high accretion rates (∼10−7 M⊙ yr−1) are ideal targets for testing this magnetospheric accretion scenario in a sustained regime. Aims. We constrained the accretion-ejection phenomena around the strongly accreting northern component of the S CrA young binary system (S CrA N) by deriving its magnetic field topology and its magnetospheric properties, and by detecting ejection signatures, if any. Methods. We led a two-week observing campaign on S CrA N with the ESPaDOnS optical spectropolarimeter at the Canada-France-Hawaii Telescope. We recorded 12 Stokes I and V spectra over 14 nights. We computed the corresponding least-squares deconvolution (LSD) profiles of the photospheric lines and performed Zeeman-Doppler imaging (ZDI). We analyzed the kinematics of noticeable emission lines, namely He I λ5876 and the first four lines of the Balmer series, which are known to trace the accretion process. Results. We found that S CrA N is a low-mass (0.8 M⊙) young (∼1 Myr) and fully convective object exhibiting strong and variable veiling (with a mean value of 7 ± 2), which suggests that the star is in a strong accretion regime. These findings could indicate a stellar evolutionary stage between Class I and Class II for S CrA N. We reconstructed an axisymmetric large-scale magnetic field (∼70% of the total energy) that is primarily located in the dipolar component, but has significant higher poloidal orders. From the narrow emission component radial velocity curve of He I λ5876, we derived a stellar rotation period of P* = 7.3 ± 0.2 days. We found a magnetic truncation radius of ∼2 R* which is significantly closer to the star than the corotation radius of ∼6 R*, suggesting that S CrA N is in an unstable accretion regime. That the truncation radius is quite smaller than the size of the Brγ line emitting region, as measured with the GRAVITY interferometer (∼8 R*), supports the presence of outflows, which is nicely corroborated by the line profiles presented in this work. Conclusions. The findings from spectropolarimetry are complementary to those provided by optical long-baseline interferometry, allowing us to construct a coherent view of the innermost regions of a young, strongly accreting star. The strong and complex magnetic field reconstructed for S CrA N is inconsistent with the observed magnetic signatures of the emission lines associated with the postshock region, however. We recommend a multitechnique synchronized campaign of several days to place more constrains on a system that varies on a timescale of about one day.Universidade Federal de Minas GeraisBrasilICX - DEPARTAMENTO DE FÍSICAUFMG2025-01-23T23:56:34Z2025-01-23T23:56:34Z2023-10-10info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articlepdfapplication/pdfhttps://doi.org/10.1051/0004-6361/2023471450004-6361http://hdl.handle.net/1843/79457https://orcid.org/0000-0002-5762-0249https://orcid.org/0000-0001-5260-7179https://orcid.org/0000-0003-3099-757Xhttps://orcid.org/0000-0002-9328-9530https://orcid.org/0000-0002-9023-7890https://orcid.org/0000-0002-9023-7890https://orcid.org/0000-0002-9628-2959https://orcid.org/0000-0002-7450-6712https://orcid.org/0000-0001-7633-7038https://orcid.org/0000-0001-7788-3727https://orcid.org/0000-0001-7397-8972https://orcid.org/0000-0001-6660-936Xhttps://orcid.org/0000-0003-3547-3783https://orcid.org/0000-0002-0493-4674engAstronomy & astrophysicsinfo:eu-repo/semantics/openAccessreponame:Repositório Institucional da UFMGinstname:Universidade Federal de Minas Gerais (UFMG)instacron:UFMGHugo NowackiEvelyne AlecianKarine PerrautBonnie ZaireColin FolsomKim PouillyJerome BouvierRajeev ManickGeorge PantolmosAlana SousaCatherine DougadosJerome BouvierGaitee HussainSilvia Helena Paixao AlencarJean-Baptiste Le Bouquin2025-01-23T23:56:35Zoai:repositorio.ufmg.br:1843/79457Repositório InstitucionalPUBhttps://repositorio.ufmg.br/oairepositorio@ufmg.bropendoar:2025-01-23T23:56:35Repositório Institucional da UFMG - Universidade Federal de Minas Gerais (UFMG)false
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