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| Paper: |
Brightening of the T Tauri star RY Tau in 1996 |
| Volume: |
154, Cool Stars, Stellar Systems and the Sun: Tenth Cambridge Workshop |
| Page: |
1808 |
| Authors: |
Zajtseva, G.; Efimov, Yu.; Petrov, P.; Ilyin, I.; Duemmler, R.; Tuominen, I. |
| Abstract: |
The T Tauri star RY Tau has increased its brightness from V=10.6' to V=9.6'in October-November 1996. In February-March 1997 the star faded to V=10.8'. High-resolution echelle spectra of RY Tau were obtained with the SOFIN spectrograph at the Nordic Optical Telescope (La Palma, Spain) at low and high brightness levels of the star. No significant changes in the photospheric lines, which are sensitive to temperature and gravity, were noticed. Polarimetric patrol of RY Tau during the fading of the star showed an increase of its intrinsic polarization from 0.5-1.0 % at high brightness to about 2 % at low brightness in the V, R and I bands. The flux radiated in Hα, Hβ and the IR Ca 2 emission lines remained about the same, in spite of the one magnitude difference in the continuum flux. These results indicate that variable obscuration of the star by circumstellar dust clouds was responsible for the brightness change of RY Tau, and that the emission line source is outside of the obscured region. |
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