Results 71 to 80 of about 106 (103)

Spectral Variability of T Tauri Stars in the Optical

Astrophysics and Space Science, 1998
We present the results of time variability analysis of the Hα, He I (λ5876 A) and Na D (λ5890, 5896 A) lines in two active T Tauri stars, DL Tau and DR Tau. The aim is the study of time behaviour of these lines, during one week, as well as possible correlations among them.
J.F. Gameiro, M.T.V.T. Lago
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The UV Variability of T Tauri Stars

1998
The T Tauri stars (TTS) are low mass pre-main-sequence stars that show an enhanced continuum and line emission when compared with main sequence stars of similar spectral types. This excess is especially noticeable at ultraviolet wavelengths, where a major fraction of the gravitational binding energy released during the accretion of the circumstellar ...
Ana I. Gómez de Castro, Merche Franqueira, Nuria Huélamo, Eva Verdugo   +3 more
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Color Indices of T Tauri Stars in Variable Circumstellar Extinction Models

Astronomy Letters, 2021
Variable circumstellar extinction models as applied to T Tauri stars are considered. In contrast to hotter UX Ori stars, for which simplified eclipse models are applicable, the star is deemed a point source of light, while the circumstellar dust clouds obscuring the star are assumed to be homogeneous.
D. V. Dmitriev, V. P. Grinin, O. Yu. Barsunova   +2 more
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Magnetic Accretion and Photopolarimetric Variability in T Tauri Stars

The Astrophysical Journal, 1996
We investigate the photopolarimetric variability of a magnetic accretion disk model for pre-main-sequence T Tauri stars. In these dynamical models, material from a magnetically truncated Keplerian disk accretes along magnetic field lines onto the stellar surface at high latitudes, producing "hot spots" on the stellar photosphere.
Kenneth Wood,, Scott J. Kenyon,, Barbara A. Whitney,, J. E. Bjorkman   +3 more
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Variability of T Tauri-like stars in NGC 2264

Astrophysics and Space Science, 1972
The variability of the T Tauri-like stars in NGC 2264 in U, B, V, R and I colours has been studied. It is found that the range of variability in amplitude in I is less than in U, B and V. A method of determining relative opacities at these wavelengths from the variability in different colours of these dust embedded stars is also described.
K. Nandy, N. Pratt
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Self‐Correlation Analysis of the Photometric Variability of T Tauri Stars

Publications of the Astronomical Society of the Pacific, 2006
T Tauri stars are variable stars that are in an early phase of evolution, in which accretion and contraction to the main sequence are still taking place. Their photometric variability is complex; it takes place on a variety of timescales, due to a variety of physical processes. Periodic variability occurs due to rotation and the presence of cool or hot
John R. Percy, Wojciech K. Gryc, Janice C.‐Y. Wong, William Herbst   +3 more
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Characteristic times of wind variability in classical T Tauri stars

Bulletin of the Crimean Astrophysical Observatory, 2013
Results of observations of short-term wind variability in the classical T Tauri stars RW Aur and DR Tau are presented. Since the H CaII emission is absorbed by the absorption component of the H∈ line, which arises in the wind at a radial velocity of about −120 km/s, the ratio of equivalent widths of the H and K emission lines of ionized calcium is used
E. V. Babina, S. A. Artemenko, P. P. Petrov, K. N. Grankin   +3 more
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Periodic variability of the T tauri star DI cephei

Astronomy Reports, 2004
Original spectroscopic and photometric observations are used together with data from the literature to compile a master light curve for DI Cep and to analyze individual data series for periodicity. The spectroscopic data reveal the period P=9.24d.
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Duplicity of some T Tauri stars and related variables

Astrophysics and Space Science, 1975
A number of double stars of which at least one component is a T Tauri star or related variable were measured in three fields: φ and χ Tauri (Taurus dark cloud); NGC 7023 and NGC 2264.
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Wind and Accretion Variability in T Tauri Stars

1998
The winds and accretion flows of classical T Tauri stars are highly variable on a variety of timescales. While much of this variability appears random, or chaotic, there are a few instances of periodic variations in the wind/accretion signatures on some stars. The periods detected are equal to either the stellar rotation period or in one instance equal
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