相关论文: Dissimilar magnetically driven accretion on the co…
The accretion and ejection of mass in pre-main sequence (PMS) stars are key processes in stellar evolution as they shape the stellar angular momentum transport necessary for the stars' stability. Magnetospheric accretion onto classical T…
The accretion process in young stellar objects (YSOs) is fundamental to the formation of stellar systems. This process governs the star's mass assembly, the transfer of angular momentum, and the shaping of the protoplanetary disc, thereby…
Classical T Tauri stars (CTTSs) are young stellar objects that accrete materials from their accretion disc influenced by their strong magnetic field. The magnetic pressure truncates the disc at a few stellar radii and forces the material to…
Multiplicity in pre-main-sequence (PMS) systems shapes circumstellar and circumbinary disks, often producing features such as inner cavities, spiral arms, and gas streamers that facilitate mass transfer between the disk and stars.…
V4046 Sagittarii AB is a close short-period classical T Tauri binary. It is a circularised and synchronised system accreting from a circumbinary disk. In 2009 it was observed as part of a coordinated program involving near-simultaneous…
We report here the first results of a multi-wavelength campaign focussing on magnetospheric accretion processes within the close binary system V4046 Sgr, hosting two partly-convective classical T Tauri stars of masses ~0.9 Msun and age ~12…
Young close binaries open central gaps in the surrounding circumbinary accretion disc, but the stellar components may still gain mass from gas crossing through the gap. It is not well understood how this process operates and how the stellar…
Binary star-formation theory predicts that close binaries (a<100 AU) will experience periodic pulsed accretion events as streams of material form at the inner edge of a circumbinary disk, cross a dynamically cleared gap, and feed…
Context. Classical T Tauri stars (cTTs) are pre-main sequence stars surrounded by an accretion disk. They host a strong magnetic field, and both magnetospheric accretion and ejection processes develop as the young magnetic star interacts…
Mass accretion from the circumstellar disk onto the protostar is a fundamental process during star formation. Measuring the mass accretion rate is particularly challenging for stars belonging to binary systems, because it is often difficult…
We present a method of determining lower limits on the masses of pre-main-sequence (PMS) stars and so constraining the PMS evolutionary tracks. This method uses the red-shifted absorption feature observed in some emission-line profiles of T…
Recent spectropolarimetric observations suggest that young low-mass stars such as classical T Tauri stars (CTTSs) possess relatively strong (~kG) magnetic field. This supports a scenario in which the final accretion onto the stellar surface…
It is now accepted that accretion onto classical T Tauri stars is controlled by the stellar magnetosphere, yet to date most accretion models have assumed that their magnetic fields are dipolar. By considering a simple steady state accretion…
We model the mass accretion rate $\dot{M}$ to stellar mass $M_*$ correlation that has been inferred from observations of intermediate to upper mass T Tauri stars---that is $\dot{M} \propto M_*^{1.3 \pm 0.3}$. We explain this correlation…
EX Lupi is the prototype of EX Lup-type stars, meaning classical T Tauri stars (cTTSs) showing luminosity bursts and outbursts of 1 to 5 magnitudes lasting for a few months to a few years. These events are ascribed to an episodic accretion…
Magnetospheric accretion is a key process that shapes the inner disks of T Tauri stars, controlling mass and angular momentum evolution. It produces strong ultraviolet and optical emission that irradiates the planet-forming environment. In…
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…
We discuss results of global 3D MHD simulations of accretion on to a rotating magnetized star with a tilted dipole magnetic field, where the accretion is driven by the magneto-rotational instability (MRI). The simulations show that…
The semi-detached eclipsing binary system, TT Hor, has a $\delta$ Sct primary component (accretor) accreting mass from the secondary star (donor). We fit an eclipsing binary model from V, B and I photometry combined with spectroscopy using…
We present low-resolution optical spectra of each component of 10 T Tauri (TT) binary systems with separations ranging from 0.9" to 3.5" and located in the Taurus star-forming region. We derive the spectral type and Halpha equivalent width…