M. V. Mekkaden1, S. Pukalenthi2, S.
Muneer2, Anju
Barbara Bastian3
1Indian Institute of Astrophysics, Bangalore - 560034,
India
2Vainu Bappu Observatory, Indian Institute of Astrophysics, Kavalur,
India
3Mother Theresa Women's University, Kodaikanal, India
Abstract. We present spectroscopic observations in the region of H alpha and Li I lines of the weak emission T Tauri star V410 Tau obtained over 1999/2000, 2002/2003 and 2003/2004 seasons. The emission strength showed rotational modulation during the 1999/2000 season in such a way that the emis- sion strength is maximum at light minimum and vice versa. This indicates that the photospheric and chromospheric active regions overlap over shorter dura- tions of time and the lifetimes of chromospheric active regions are far shorter than the photospheric active regions. But the observations obtained during the 2003/2004 season do not follow the trend observed at earlier seasons. This can be due to the change in the location of chromospheric active regions. Another possibility is the occurrence of a major change in the photospheric active re- gions that have caused a redistribution of photospheric as well as chromospheric active regions. The Li I EW does not show any appreciable change over the four-year period.
Keywords : pre-main sequence stars, chromospheric activity, starspots