English
Related papers

Related papers: New Insights: the Accretion Process and Variable W…

200 papers

From a long time series of high resolution (R=115,000) HARPS spectra and simultaneous broad-band photometry, we report new evidence for magnetospheric accretion as well as ejection processes in the nearly edge-on classical T Tauri star AA…

Depending on whether a T Tauri star accretes material from its circumstellar disk or not, different X-ray emission properties can be found. The accretion shocks produce cool heating of the plasma, contributing to the soft X-ray emission…

Solar and Stellar Astrophysics · Physics 2016-02-24 Ignacio Bustamante , Bruno Merín , Hervé Bouy , Carlo Manara , Álvaro Ribas , Pablo Riviere-Marichalar

The high opacity of He I 10830 makes it an exceptionally sensitive probe of the inner wind geometry of accreting T Tauri stars. In this line blueshifted absorption below the continuum results from simple scattering of stellar photons, a…

Astrophysics · Physics 2008-11-26 John Kwan , Suzan Edwards , William Fischer

Classical T Tauri stars (CTTSs) are variable in different time-scales. One type of variability is possibly connected with the accretion of matter through the Rayleigh-Taylor instability that occurs at the interface between an accretion disc…

Solar and Stellar Astrophysics · Physics 2015-06-12 Ryuichi Kurosawa , Marina M. Romanova

Classical T Tauri stars (CTTS) are young (< 10 Myr), cool stars that actively accrete matter from a disk. They show strong, broad and asymmetric, atomic FUV emission lines. Neither the width, nor the line profile is understood. Likely,…

Solar and Stellar Astrophysics · Physics 2014-08-18 H. M. Günther , N. S. Brickhouse , A. K. Dupree , S. J. Wolk , P. C. Schneider , G. J. M. Luna

The Classical T Tauri Star (CTTS) stage is a critical phase of the star and planet formation process. In an effort to better understand the mass accretion process, which can dictate further stellar evolution and planet formation, a…

TWA 3A is the most recent addition to a small group of young binary systems that both actively accrete from a circumbinary disk and have spectroscopic orbital solutions. As such, it provides a unique opportunity to test binary accretion…

Solar and Stellar Astrophysics · Physics 2017-06-23 Benjamin M. Tofflemire , Robert D. Mathieu , Gregory J. Herczeg , Rachel L. Akeson , David R. Ciardi

T Tauri stars produce broad Lyman-alpha emission lines that contribute $\sim$88% of the total UV flux incident on the inner circumstellar disks. Lyman-alpha photons are generated at the accretion shocks and in the protostellar chromospheres…

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…

Astrophysics · Physics 2009-11-11 S. G. Gregory , M. Jardine , I. Simpson , J. -F. Donati

We present a three-dimensional, time-dependent, MHD simulation of the short-term interaction between a protoplanetary disk and the stellar corona in a T Tauri system. The simulation includes the stellar magnetic field, self-consistent…

Solar and Stellar Astrophysics · Physics 2023-06-07 Ofer Cohen , Cecilia Garraffo , Jeremy Drake , Kristina Monsch , Igor Sokolov , Julian Alvarado-Gomez , Federico Fraschetti

We discuss key observational signatures of Classical T Tauri stars (CTTSs) accreting through Rayleigh-Taylor instability, which occurs at the interface between an accretion disk and a stellar magnetosphere. In this study, the results of…

Solar and Stellar Astrophysics · Physics 2013-07-16 Ryuichi Kurosawa , M. M. Romanova

Classical T Tauri Stars (CTTSs) are highly variable stars that possess gas- and dust-rich disks from which planets form. Much of their variability is driven by mass accretion from the surrounding disk, a process that is still not entirely…

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…

Interpreting the short-timescale variability of the accreting, young, low-mass stars known as Classical T Tauri stars remains an open task. Month-long, continuous light curves from the Transiting Exoplanet Survey Satellite (\textit{TESS})…

Solar and Stellar Astrophysics · Physics 2022-08-24 Connor E. Robinson , Catherine C. Espaillat , Joseph E. Rodriguez

Classical T Tauri stars (CTTSs) are young low-mass stellar objects accreting mass from their circumstellar disks. They are characterized by high levels of coronal activity as revealed by X-ray observations. This activity may affect the disk…

The structure and spectrum of the accretion shock have been self-consistently simulated for a wide range of parameters typical for Classical T Tauri Stars (CTTS). Radiative cooling of the shocked gas was calculated, taking into account the…

Solar and Stellar Astrophysics · Physics 2018-01-09 Alexandr Dodin

In classical T Tauri stars, X-rays are produced by two plasma components: a hot low-density plasma, with frequent flaring activity, and a high-density lower temperature plasma. The former is coronal plasma related to the stellar magnetic…

Solar and Stellar Astrophysics · Physics 2015-05-14 C. Argiroffi , A. Maggio , G. Peres , J. J. Drake , J. Lopez Santiago , S. Sciortino , B. Stelzer

The rotation period of classical T Tauri stars (CTTS) represents a longstanding puzzle. While young low-mass stars show a wide range of rotation periods, many CTTS are slow rotators, spinning at a small fraction of break-up, and their…

Solar and Stellar Astrophysics · Physics 2015-05-20 C. Zanni , J. Ferreira

Diagnostics of electron temperature (T_e), electron density (n_e), and hydrogen column density (N_H) from the Chandra High Energy Transmission Grating spectrum of He-like Ne IX in TW Hydrae (TW Hya), in conjunction with a classical…

Solar and Stellar Astrophysics · Physics 2015-06-12 N. S. Brickhouse , S. R. Cranmer , A. K. Dupree , H. M. Günther , G. J. M. Luna , S. J. Wolk

During a stellar tidal disruption event (TDE), an accretion disk forms as stellar debris returns to the disruption site and circularizes. Rather than being confined within the circularizing radius, the disk can spread to larger radii to…

High Energy Astrophysical Phenomena · Physics 2014-03-11 Rong-Feng Shen , Christopher D. Matzner