Optical Spectroscopic Monitoring Observations of a T Tauri Star V409 Tau

• 作者: Hinako Akimoto Yoichi Itoh
• 来源期刊: 天文学与天体物理学国际期刊(英文)
• 学科: 地球科学
• 关键词: STAR Formation Pre-Main Sequence STARS T TAURI STARS
• 年，卷（期）: 2019,（3）
• 页码范围: 321-334
• 页数: 14页
• 分类号: P1

摘要

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 Hαemission 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 Hαemission 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 Hαemission line indicates unsteady mass accretion from the circumstellar disk to the central star.