The magnetic propeller accretion regime of LkCa 15

J.-F. Donati; J. Bouvier; S. H. Alencar; C. Hill; A. Carmona; C. P. Folsom; F. Ménard; S. G. Gregory; G. A. Hussain; K. Grankin; C. Moutou; L. Malo; M. Takami; G. J. Herczeg

doi:10.1093/mnrasl/sly207

The magnetic propeller accretion regime of LkCa 15

J.-F. Donati (Lead / Corresponding author), J. Bouvier, S. H. Alencar, C. Hill, A. Carmona, C. P. Folsom, F. Ménard, S. G. Gregory, G. A. Hussain, K. Grankin, C. Moutou, L. Malo, M. Takami, G. J. Herczeg

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39 Citations (Scopus)

Abstract

We present a spectropolarimetric study of the classical T Tauri star (cTTS) LkCa 15 investigating the large-scale magnetic topology of the central star and the way the field connects to the inner regions of the accretion disc. We find that the star hosts a strong poloidal field with a mainly axisymmetric dipole component of 1.35 kG, whereas the mass accretion rate at the surface of the star is 10^-9.2 M_☉ yr^-1. It implies that the magnetic field of LkCa 15 is able to evacuate the central regions of the disc up to a distance of 0.07 au at which the Keplerian orbital period equals the stellar rotation period. Our results suggest that LkCa 15, like the lower mass cTTS AA Tau, interacts with its disc in a propeller mode, a regime supposedly very efficient at slowing down the rotation of cTTSs hosting strong dipolar fields....

Original language	English
Pages (from-to)	L1-L5
Number of pages	5
Journal	Monthly Notices of the Royal Astronomical Society: Letters
Volume	483
Issue number	1
Early online date	10 Nov 2018
DOIs	https://doi.org/10.1093/mnrasl/sly207
Publication status	Published - Feb 2019

Keywords

stars: formation
stars: imaging
stars: individual: LkCa 15
stars: magnetic fields
techniques: polarimetric

ASJC Scopus subject areas

Astronomy and Astrophysics
Space and Planetary Science

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10.1093/mnrasl/sly207

https://arxiv.org/pdf/1811.04810.pdf

Cite this

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title = "The magnetic propeller accretion regime of LkCa 15",

abstract = "We present a spectropolarimetric study of the classical T Tauri star (cTTS) LkCa 15 investigating the large-scale magnetic topology of the central star and the way the field connects to the inner regions of the accretion disc. We find that the star hosts a strong poloidal field with a mainly axisymmetric dipole component of 1.35 kG, whereas the mass accretion rate at the surface of the star is 10-9.2 M☉ yr-1. It implies that the magnetic field of LkCa 15 is able to evacuate the central regions of the disc up to a distance of 0.07 au at which the Keplerian orbital period equals the stellar rotation period. Our results suggest that LkCa 15, like the lower mass cTTS AA Tau, interacts with its disc in a propeller mode, a regime supposedly very efficient at slowing down the rotation of cTTSs hosting strong dipolar fields....",

keywords = "stars: formation, stars: imaging, stars: individual: LkCa 15, stars: magnetic fields, techniques: polarimetric",

author = "J.-F. Donati and J. Bouvier and Alencar, {S. H.} and C. Hill and A. Carmona and Folsom, {C. P.} and F. M{\'e}nard and Gregory, {S. G.} and Hussain, {G. A.} and K. Grankin and C. Moutou and L. Malo and M. Takami and Herczeg, {G. J.}",

year = "2019",

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doi = "10.1093/mnrasl/sly207",

language = "English",

volume = "483",

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T1 - The magnetic propeller accretion regime of LkCa 15

AU - Donati, J.-F.

AU - Bouvier, J.

AU - Alencar, S. H.

AU - Hill, C.

AU - Carmona, A.

AU - Folsom, C. P.

AU - Ménard, F.

AU - Gregory, S. G.

AU - Hussain, G. A.

AU - Grankin, K.

AU - Moutou, C.

AU - Malo, L.

AU - Takami, M.

AU - Herczeg, G. J.

PY - 2019/2

Y1 - 2019/2

N2 - We present a spectropolarimetric study of the classical T Tauri star (cTTS) LkCa 15 investigating the large-scale magnetic topology of the central star and the way the field connects to the inner regions of the accretion disc. We find that the star hosts a strong poloidal field with a mainly axisymmetric dipole component of 1.35 kG, whereas the mass accretion rate at the surface of the star is 10-9.2 M☉ yr-1. It implies that the magnetic field of LkCa 15 is able to evacuate the central regions of the disc up to a distance of 0.07 au at which the Keplerian orbital period equals the stellar rotation period. Our results suggest that LkCa 15, like the lower mass cTTS AA Tau, interacts with its disc in a propeller mode, a regime supposedly very efficient at slowing down the rotation of cTTSs hosting strong dipolar fields....

AB - We present a spectropolarimetric study of the classical T Tauri star (cTTS) LkCa 15 investigating the large-scale magnetic topology of the central star and the way the field connects to the inner regions of the accretion disc. We find that the star hosts a strong poloidal field with a mainly axisymmetric dipole component of 1.35 kG, whereas the mass accretion rate at the surface of the star is 10-9.2 M☉ yr-1. It implies that the magnetic field of LkCa 15 is able to evacuate the central regions of the disc up to a distance of 0.07 au at which the Keplerian orbital period equals the stellar rotation period. Our results suggest that LkCa 15, like the lower mass cTTS AA Tau, interacts with its disc in a propeller mode, a regime supposedly very efficient at slowing down the rotation of cTTSs hosting strong dipolar fields....

KW - stars: formation

KW - stars: imaging

KW - stars: individual: LkCa 15

KW - stars: magnetic fields

KW - techniques: polarimetric

UR - https://arxiv.org/abs/1811.04810

UR - https://ui.adsabs.harvard.edu/abs/2019MNRAS.483L...1D/abstract

UR - http://www.scopus.com/inward/record.url?scp=85062430631&partnerID=8YFLogxK

U2 - 10.1093/mnrasl/sly207

DO - 10.1093/mnrasl/sly207

M3 - Article

SN - 1745-3925

VL - 483

SP - L1-L5

JO - Monthly Notices of the Royal Astronomical Society: Letters

JF - Monthly Notices of the Royal Astronomical Society: Letters

IS - 1

ER -

The magnetic propeller accretion regime of LkCa 15

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Gregory, Scott

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The magnetic propeller accretion regime of LkCa 15

Abstract

Keywords

ASJC Scopus subject areas

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Gregory, Scott

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