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Related papers: Classical T Tauri stars: magnetic fields, coronae,…

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We have modeled the rotational modulation of X-ray emission from T Tauri stars assuming that they have isothermal, magnetically confined coronae. By extrapolating surface magnetograms we find that T Tauri coronae are compact and clumpy,…

Astrophysics · Physics 2007-05-23 S. G. Gregory , M. Jardine , A. Collier Cameron , J. -F. Donati

ZDI studies have shown that the magnetic fields of T Tauri stars can be significantly more complex than a simple dipole and can vary markedly between sources. We collect and summarize the magnetic field topology information obtained to date…

Solar and Stellar Astrophysics · Physics 2015-06-05 S. G. Gregory , J. -F. Donati , J. Morin , G. A. J. Hussain , N. J. Mayne , L. A. Hillenbrand , M. Jardine

The magnetic interaction between a classical T Tauri star and its surrounding accretion disk is thought to influence its rotational evolution. We use 2.5D magnetohydrodynamic, axisymmetric simulations of star-disk interaction, computed via…

Solar and Stellar Astrophysics · Physics 2022-04-20 Lewis G. Ireland , Sean P. Matt , Claudio Zanni

We have modelled the rotational modulation of X-ray emission from T Tauri stars assuming that they have isothermal, magnetically confined coronae. By extrapolating surface magnetograms we find that T Tauri coronae are compact and clumpy,…

Astrophysics · Physics 2009-11-11 S. G. Gregory , M. Jardine , A. Collier Cameron , J. -F. Donati

Accretion onto Classical T Tauri stars is thought to take place through the action of magnetospheric processes, with gas in the inner disk being channeled onto the star's surface by the stellar magnetic field lines. Young stars are known to…

Solar and Stellar Astrophysics · Physics 2017-04-05 Connor Robinson , James Owen , Catherine Espaillat , Fred Adams

Buoyancy of the fossil magnetic field in the accretion disks of young stars is investigated. It is assumed that the Parker instability leads to the formation of slender flux tubes of toroidal magnetic field in the regions of effective…

Solar and Stellar Astrophysics · Physics 2018-01-01 Sergey A. Khaibrakhmanov , Alexander E. Dudorov

Evidence of magnetic interaction between late-type stars and close-in giant planets is provided by the observations of stellar hot spots rotating synchronously with the planets and showing an enhancement of chromospheric and X-ray fluxes.…

Solar and Stellar Astrophysics · Physics 2015-05-13 A. F. Lanza

We examine how accretion on to T Tauri stars may be modulated by a time-dependent `magnetic gate' where the inner edge of the accretion disc is disrupted by a varying stellar field. We show that magnetic field variations on time-scales…

Astrophysics · Physics 2015-06-24 C. J. Clarke , P. J. Armitage , K. W. Smith , J. E. Pringle

Classical T Tauri stars (CTTSs) accrete matter from the inner edge of their surrounding circumstellar disks. The impact of the accretion material on the stellar atmosphere results in a strong shock, which causes emission from the X-ray to…

Solar and Stellar Astrophysics · Physics 2018-10-17 P. C. Schneider , H. M. Günther , J. Robrade , J. H. M. M. Schmitt , M. Güdel

We study the global bending modes of a thin annular disc subject to both an internally generated magnetic field and a magnetic field due to a dipole embedded in the central star with axis aligned with the disc rotation axis. When there is a…

Astrophysics · Physics 2007-05-23 Vasso Agapitou , John C. B. Papaloizou , Caroline Terquem

Accreting T Tauri stars are observed to be less luminous in X-rays than non-accretors, an effect that has been detected in various star forming regions. To explain this we have combined, for the first time, a radiative transfer code with an…

Astrophysics · Physics 2009-06-23 S. G. Gregory , K. Wood , M. Jardine

Transition disc systems are young stars that appear to be on the verge of dispersing their protoplanetary discs. We explore the nature of these systems by comparing the stellar accretion rates and disc masses of transition discs and normal…

Solar and Stellar Astrophysics · Physics 2015-04-22 Joan R. Najita , Sean M. Andrews , James Muzerolle

How T Tauri stars remain slowly rotating while still accreting material is a long-standing puzzle. Current models suggest that these stars may lose angular momentum through magnetospheric ejections of disk material (MEs) and…

Solar and Stellar Astrophysics · Physics 2025-04-30 Lukas Gehrig , Eric Gaidos , Laura Venuti , Ann Marie Cody , Neal J. Turner

The magnetic field of the classical T Tauri star BP Tau can be approximated as a superposition of dipole and octupole moments with respective strengths of the polar magnetic fields of 1.2 kG and 1.6 kG (Donati et al. 2008). We adopt the…

Solar and Stellar Astrophysics · Physics 2015-05-20 M. Long , M. M. Romanova , A. K. Kulkarni , J. -F. Donati

The rotational evolution of accreting pre-main-sequence stars is influenced by its magnetic interaction with its surrounding circumstellar disk. Using the PLUTO code, we perform 2.5D magnetohydrodynamic, axisymmetric, time-dependent…

Solar and Stellar Astrophysics · Physics 2021-01-06 Lewis G. Ireland , Claudio Zanni , Sean P. Matt , George Pantolmos

We investigate the change in stellar magnetic topology across the fully-convective boundary and its effects on coronal properties. We consider both the magnitude of the open flux that influences angular momentum loss in the stellar wind and…

Solar and Stellar Astrophysics · Physics 2012-07-11 Pauline Lang , Moira Jardine , Jean-Francois Donati , Julien Morin , Aline Vidotto

Classical T Tauri stars with ages of less than 10 Myr possess accretion discs. Magnetohydrodynamic processes at the boundary between the disc and the stellar magnetosphere control the accretion and ejections gas flows. We carried out a long…

Classical T Tauri stars (CTTS) accrete material from their discs through their magnetospheres. The geometry of the accretion flow strongly depends on the magnetic obliquity, i.e., the angle between the rotational and magnetic axes. We aim…

Solar and Stellar Astrophysics · Physics 2020-07-15 Pauline McGinnis , Jérôme Bouvier , Florian Gallet

T Tauri stars are known to be magnetically active stars subject to strong flares observed in X-rays. These flares are likely due to intense magnetic reconnection events during which a part of the stored magnetic energy is converted into…

High Energy Astrophysical Phenomena · Physics 2024-04-26 Valentin Brunn , Christian Rab , Alexandre Marcowith , Christophe Sauty , Marco Padovani , Chadi Meskini

Magnetic fields play a crucial role at all stages of the formation of low mass stars and planetary systems. In the final stages, in particular, they control the kinematics of in-falling gas from circumstellar discs, and the launching and…

Solar and Stellar Astrophysics · Physics 2015-05-19 S. G. Gregory , M. Jardine , C. G. Gray , J. -F. Donati