Related papers: Accretion and magnetism on young eccentric binarie…
Young stars interact with their accretion disk through their strong magnetosphere. We investigate the magnetospheric accretion process in the young stellar system DoAr 44. We monitored the system over several rotational cycles, combining…
The early stages of the pre-Main-Sequence (PMS) evolution of young stars are characterized by a substantial interaction between the central star and the surrounding disk. Among the processes that take place, the accretion of material from…
We present numerical solutions of the collapse of prestellar cores that lead to the formation and evolution of circumstellar disks. The disk evolution is then followed for up to three million years. A variety of models of different initial…
The propeller regime of disk accretion to a rapidly rotating magnetized star is investigated here for the first time by axisymmetric 2.5D magnetohydrodynamic simulations. An expanded, closed magnetosphere forms in which the magnetic field…
The accretion/ejection processes in T-Tauri stars are fundamental to their physical evolution, while also impacting the properties and evolution of the circumstellar material at a time when planet formation takes place. To this date,…
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…
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…
From observations collected with the ESPaDOnS & NARVAL spectropolarimeters at CFHT and TBL, we report the detection of Zeeman signatures on the prototypical classical TTauri star AATau, both in photospheric lines and accretion-powered…
We perform numerical simulations to investigate high-power wind accretion in massive binary systems undergoing enhanced mass-loss episodes. The primary star is taken in the mass range $M_{1} = 60$--$90\,\mathrm{M_{\odot}}$, while the…
Classical T Tauri stars are surrounded by a circumstellar disk from which they are accreting material. This process is essential in the formation of Sun-like stars. Although often described with simple and static models, the accretion…
We present observations of the classical T Tauri star DO Tau collected with the near-infrared SPIRou spectropolarimeter and precision velocimeter at the Canada-France-Hawaii Telescope from early 2020 to late 2025. Circularly polarized…
Magnetospheric accretion is an important process for a wide range of astrophysical systems, and may play a role in the formation of gas giant planets. Extending the formalism describing stellar magnetospheric accretion into the planetary…
We present a spectral analysis of 30 T Tauri stars observed with the Hamilton echelle spectrograph over more than a decade. One goal is to test magnetospheric accretion model predictions. Observational evidence previously published…
Aims: Our goal is to investigate how the strength of episodic accretion bursts depends on eccentricity. Methods: We investigate the binary trigger hypothesis in longer-period (>20yr) binaries by carrying out three-dimensional…
The inner region of the accretion disk around a magnetized star is subjected to magnetic torques that induce warping and precession of the disk. These torques arise from interactions between the stellar field and the induced electric…
We present numerical simulations of circumbinary accretion onto eccentric and circular binaries using the moving-mesh code AREPO. This is the first set of simulations to tackle the problem of binary accretion using a finite-volume scheme on…
Physical processes that redistribute or remove angular momentum from protoplanetary disks can drive mass accretion onto the star and affect the outcome of planet formation. Despite ubiquitous evidence that protoplanetary disks are engaged…
Observations of T Tauri stars and young brown dwarfs suggest that the accretion rates of their disks scale strongly with the central stellar mass, approximately $\mdot \propto M_*^2$. No dependence of accretion rate on stellar mass is…
Recent theoretical work has shown that the pre-main-sequence (PMS) evolution of stars is much more complex than previously envisioned. Instead of the traditional steady, one-dimensional solution, accretion may be episodic and not…
Planets are thought to form at the early stage of stellar evolution when the mass accretion is still ongoing. RY Tau is a T Tauri type star at the age of a few Myr, with accretion disc seen at high inclination, so that line of sight crosses…