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Related papers: Time-Variable Accretion in the TW Hya Star/Disk Sy…

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Time-domain spectroscopy of the classical accreting T Tauri star, TW Hya, covering a decade and spanning the far UV to the near-infrared spectral regions can identify the radiation sources, the atmospheric structure produced by…

Solar and Stellar Astrophysics · Physics 2015-06-19 A. K. Dupree , N. S. Brickhouse , S. R. Cranmer , P. Berlind , J. Strader , G. H. Smith

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

The nearest accreting T Tauri star, TW Hya was observed with spectroscopic and photometric measurements simultaneous with a long se gmented exposure using the CHANDRA satellite. Contemporaneous optical photometry from WASP-S indicates a…

The TW Hya system is perhaps the closest analog to the early solar nebula. We have used the Very Large Array to image TW Hya at wavelengths of 7mm and 3.6 cm with resolutions 0.1 arcseconds (about 5 AU) and 1.0 arcseconds (about 50 AU),…

Astrophysics · Physics 2009-10-31 D. J. Wilner , P. T. P. Ho , J. H. Kastner , L. F. Rodriguez

The proliferation of high time-resolution and decades-long monitoring of classical T Tauri stars provides a vast opportunity to test the variability of the star-disk connections. However, most monitoring surveys use single broad-band…

This is the final photometric study of TW Hya based on new MOST satellite observations. During 2014 and 2017 the light curves showed stable 3.75 and 3.69 d quasi-periodic oscillations, respectively. Both values appear to be closely related…

A continuous set of echelle spectra of TW Hya, taken with the MIKE spectrograph on the Magellan2/Clay telescope at Las Campanas Observatory in April 2006 reveals systematic variations in the flux, velocity, and profile of the H-alpha…

Astrophysics · Physics 2007-05-23 A. K. Dupree , E. H. Avrett , N. S. Brickhouse , S. R. Cranmer , T. Szalai

We present high resolution X-ray spectra of the X-ray bright classical T Tauri star, TW Hydrae, covering the wavelength range of 1.5-25 AA. The differential emission measure derived from fluxes of temperature-sensitive emission lines shows…

A two dimensional numerical model in the axisymmetric approximation that describes the flow structure in the magnetosphere of the white dwarf in the EX Hya system has been developed. Results of simulations show that the accretion in EX Hya…

Solar and Stellar Astrophysics · Physics 2019-12-23 P. B. Isakova , A. G. Zhilkin , D. V. Bisikalo , A. N. Semena , M. G. Revnivtsev

We present an analysis of the accretion properties of the members of the TW Hydrae association. The Halpha emission line profile provides explicit evidence of an active accretion flow in 3 out of 23 observed members of the association; we…

Astrophysics · Physics 2007-05-23 James Muzerolle , Lynne Hillenbrand , Nuria Calvet , Lee Hartmann , Cesar Briceno

As a continuation of our previous studies in 2007 and 2008, new photometric observations of the T Tauri star TW Hya obtained by the MOST satellite and the ASAS project over 40 days in 2009 with temporal resolution of 0.2 days are presented.…

Accretion is a fundamental process in star formation. Although the time evolution of accretion remains a matter of debate, observations and modelling studies suggest that episodic outbursts of strong accretion may dominate the formation of…

We investigate the origin of photometric variability in the classical T Tauri star TW Hya by comparing light curves obtained by TESS and ground-based telescopes with light curves created using three-dimensional (3D) magnetohydrodynamic…

Solar and Stellar Astrophysics · Physics 2025-01-24 M. M. Romanova , C. C. Espaillat , J. Wendeborn , J. -F. Donati , P. P. Petrov , R. V. E. Lovelace

We present arcsecond-scale Submillimeter Array observations of the CO(3-2) line emission from the disks around the young stars HD 163296 and TW Hya at a spectral resolution of 44 m/s. These observations probe below the ~100 m/s turbulent…

Solar and Stellar Astrophysics · Physics 2015-05-20 A. Meredith Hughes , David J. Wilner , Sean M. Andrews , Chunhua Qi , Michiel R. Hogerheijde

We present Very Large Array observations at 3.5 cm of the nearby young star TW Hya that show the emission is constant in time over weeks, months and years, and spatially resolved with peak brightness temperature ~10 K at ~0.25 (15 AU)…

Astrophysics · Physics 2009-11-13 D. J. Wilner , P. D'Alessio , N. Calvet , M. J. Claussen , L. Hartmann

We report the results of a synoptic study of the photometric and spectroscopic variability of the classical T Tauri star AA Tau on timescales ranging from a few hours to several weeks. Emission lines show both infall and outflow signatures…

Using the HST Fine Guidance Sensor, we have measured a high precision astrometric parallax of the cataclysmic variable EX Hydrae, pi=15.50+-0.29mas. From the wavelength-integrated accretion-induced energy flux, we derive a quiescent…

Astrophysics · Physics 2009-11-10 K. Beuermann , Th. E. Harrison , B. E. McArthur , G. F. Benedict , B. T. Gaensicke

We examine the long-term spectroscopic and photometric variability of EX~Lupi and TW~Hya, studying the presence of stable accretion and the role it plays in the observed variability. Analysing the velocity modulations of the emission lines…

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