Star-disk interactions in the strongly accreting T Tauri star S CrA N
| dc.creator | Hugo Nowacki | |
| dc.creator | Evelyne Alecian | |
| dc.creator | Karine Perraut | |
| dc.creator | Bonnie Zaire | |
| dc.creator | Colin Folsom | |
| dc.creator | Kim Pouilly | |
| dc.creator | Jerome Bouvier | |
| dc.creator | Rajeev Manick | |
| dc.creator | George Pantolmos | |
| dc.creator | Alana Sousa | |
| dc.creator | Catherine Dougados | |
| dc.creator | Jerome Bouvier | |
| dc.creator | Gaitee Hussain | |
| dc.creator | Silvia Helena Paixao Alencar | |
| dc.creator | Jean-Baptiste Le Bouquin | |
| dc.date.accessioned | 2025-01-23T23:56:34Z | |
| dc.date.accessioned | 2025-09-08T23:22:46Z | |
| dc.date.available | 2025-01-23T23:56:34Z | |
| dc.date.issued | 2023-10-10 | |
| dc.format.mimetype | ||
| dc.identifier.doi | https://doi.org/10.1051/0004-6361/202347145 | |
| dc.identifier.issn | 0004-6361 | |
| dc.identifier.uri | https://hdl.handle.net/1843/79457 | |
| dc.language | eng | |
| dc.publisher | Universidade Federal de Minas Gerais | |
| dc.relation.ispartof | Astronomy & astrophysics | |
| dc.rights | Acesso Aberto | |
| dc.subject | Estrelas - Campos magnéticos | |
| dc.subject | Estrelas T Tauri | |
| dc.subject | Astronomia | |
| dc.subject.other | Stars: variables: T Tauri | |
| dc.subject.other | Stars: individual: S CrA N | |
| dc.subject.other | Herbig Ae/Be | |
| dc.subject.other | Stars: magnetic field | |
| dc.subject.other | Techniques: spectroscopic | |
| dc.subject.other | Techniques: polarimetric | |
| dc.subject.other | Accretion | |
| dc.subject.other | Accretion disks | |
| dc.title | Star-disk interactions in the strongly accreting T Tauri star S CrA N | |
| dc.type | Artigo de periódico | |
| local.citation.epage | 16 | |
| local.citation.spage | 1 | |
| local.citation.volume | 678 | |
| local.description.resumo | 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. | |
| local.identifier.orcid | https://orcid.org/0000-0002-5762-0249 | |
| local.identifier.orcid | https://orcid.org/0000-0001-5260-7179 | |
| local.identifier.orcid | https://orcid.org/0000-0003-3099-757X | |
| local.identifier.orcid | https://orcid.org/0000-0002-9328-9530 | |
| local.identifier.orcid | https://orcid.org/0000-0002-9023-7890 | |
| local.identifier.orcid | https://orcid.org/0000-0002-9023-7890 | |
| local.identifier.orcid | https://orcid.org/0000-0002-9628-2959 | |
| local.identifier.orcid | https://orcid.org/0000-0002-7450-6712 | |
| local.identifier.orcid | https://orcid.org/0000-0001-7633-7038 | |
| local.identifier.orcid | https://orcid.org/0000-0001-7788-3727 | |
| local.identifier.orcid | https://orcid.org/0000-0001-7397-8972 | |
| local.identifier.orcid | https://orcid.org/0000-0001-6660-936X | |
| local.identifier.orcid | https://orcid.org/0000-0003-3547-3783 | |
| local.identifier.orcid | https://orcid.org/0000-0002-0493-4674 | |
| local.publisher.country | Brasil | |
| local.publisher.department | ICX - DEPARTAMENTO DE FÍSICA | |
| local.publisher.initials | UFMG | |
| local.url.externa | https://www.aanda.org/articles/aa/pdf/2023/10/aa47145-23.pdf |