Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Dynamics of wind and the dusty environments in the accreting T Tauri
  stars RY Tau and SU Aur   Classical T Tauri stars with ages of less than 10 Myr possess accretion
discs. Magnetohydrodynamic processes at the boundary between the disc and the
stellar magnetosphere control the accretion and ejections gas flows. We carried
out a long series of simultaneous spectroscopic and photometric observations of
the classical T Tauri stars RY Tau and SU Aur with the aim to quantify the
accretion and outflow dynamics at time scales from days to years. It is shown
that dust in the disc wind is the main source of photometric variability of
these stars. In RY Tau we observed a new effect: during events of enhanced
outflow the circumstellar extinction gets lower. The characteristic time of
changes in outflow velocity and stellar brightness indicates that the obscuring
dust is near the star. The outflow activity in both stars is changing on a time
scale of years. Periods of quiescence in H$\alpha$ profile variability were
observed during 2015-2016 season in RY Tau and during 2016-2017 season in SU
Aur. We interpret these findings in the framework of the magnetospheric
accretion model, and discuss how the global stellar magnetic field may
influence the long-term variations of the outflow activity.

23
The categories of this paper are: solv-int
29
The categories of this paper are: funct-an
36
The categories of this paper are: cmp-lg
34
The categories of this paper are: chem-ph
22
The categories of this paper are: chao-dyn
32
The categories of this paper are: atom-ph
30
The categories of this paper are: q-alg
4
The categories of this paper are: cond-mat
9
The categories of this paper are: nlin
17
The categories of this paper are: q-fin
37
The categories of this paper are: supr-con
13
The categories of this paper are: quant-ph
21
The categories of this paper are: adap-org
0
The categories of this paper are: hep-ph
28
The categories of this paper are: alg-geom
35
The categories of this paper are: mtrl-th