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We report the results of optical spectroscopic monitoring observations of a T Tauri star, V409 Tau. A previous photometric study indicated that this star experienced dimming events due to the obscuration of light from the central star with a distorted circumstellar disk. We conducted medium-resolution (R ~10,000) spectroscopic observations with 2-m Nayuta telescope at Nishi-Harima Astronomical Observatory. Spectra were obtained in 18 nights between November 2015 and March 2016. Several absorption lines such as Ca I and Li, and the H alpha emission line were confirmed in the spectra. The Ic-band magnitudes of V409 Tau changed by approximately 1 magnitude during the observation epoch. The equivalent widths of the five absorption lines are roughly constant despite changes in the Ic-band magnitudes. We conclude that the light variation of the star is caused by the obscuration of light from the central star with a distorted circumstellar disk, based on the relationship between the equivalent widths of the absorption lines and the Ic-band magnitudes. The blue component of the H alpha emission line was dominant during the observation epoch, and an inverse P Cygni profile was observed in eight of the spectra. The time-variable inverse P Cygni profile of the H alpha emission line indicates unsteady mass accretion from the circumstellar disk to the central star.
The variability of young stellar objects is mostly driven by star-disk interactions. In long-term photometric monitoring of the accreting T Tauri star GI Tau, we detect extinction events with typical depths of $Delta V sim 2.5$ mag that last for days
We present new brightness and magnetic images of the weak-line T Tauri star V410 Tau, made using data from the NARVAL spectropolarimeter at Telescope Bernard Lyot (TBL). The brightness image shows a large polar spot and significant spot coverage at l
We present the discovery of two extended $sim$0.12 mag dimming events of the weak-lined T-Tauri star V1334. The start of the first event was missed but came to an end in late 2003, and the second began in February 2009, and continues as of November 2
Context. Classical T Tauri stars (cTTs) are pre-main sequence stars surrounded by an accretion disk. They host a strong magnetic field, and both magnetospheric accretion and ejection processes develop as the young magnetic star interacts with its dis
We use Spitzer data to infer that the small infrared excess of V819 Tau, a weak-lined T Tauri star in Taurus, is real and not attributable to a companion 10 arcsec to the south. We do not confirm the mid-infrared excess in HBC 427 and V410 X-ray 3, w