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arXiv · 1509.04966

Orbital motions and light curves of young binaries XZ Tau and VY Tau

A. V. Dodin·N. V. Emelyanov·A. V. Zharova·S. A. Lamzin·E. V. Malogolovets·J. M. Roe
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Abstract

The results of our speckle interferometric observations of young binaries VY Tau and XZ Tau are presented. For the first time, we found a relative displacement of VY Tau components as well as a preliminary orbit for XZ Tau. It appeared that the orbit is appreciably non-circular and is inclined by $i \lesssim 47^o$ from the plane of the sky. It means that the rotation axis of XZ Tau A and the axis of its jet are significantly non-perpendicular to the orbital plane. We found that the average brightness of XZ Tau had been increasing from the beginning of the last century up to the mid-thirties and then it decreased by $\Delta B > 2$ mag. The maximal brightness has been reached significantly later on the time of periastron passage. The total brightness of XZ Tau's components varied in a non-regular way from 1970 to 1985 when eruptions of hot gas from XZ Tau A presumably had occurred. In the early nineties the variations became regular following which a chaotic variability had renewed. We also report that a flare activity of VY Tau has resumed after 40 yr pause, parameters of the previous and new flares are similar, and the flares are related with the A component.

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A. V. Dodin, N. V. Emelyanov, A. V. Zharova, S. A. Lamzin, E. V. Malogolovets, J. M. Roe. 2015-09-16. Orbital motions and light curves of young binaries XZ Tau and VY Tau. https://doi.org/10.1134/s1063773716010035

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