http://arxiv.org/abs/1712.09882
Molecular absorption bands are estimators of stellar activity and spot cycles on magnetically active stars. We have previously introduced a new color index that compare absorption strength of the titanium oxide (TiO) at 567 nm with nearby continuum. In this paper we implement this index to measure long-term activity variations and the statistical properties of the index in a sample of 302 solar-type stars from the HARPS planet search program. The results indicate a pattern of change in star’s activity, covers a range of periods from 2 years up to 17 years.
F. Azizi and M. Mirtorabi
Fri, 29 Dec 2017
14/65
Comments: 17 pages, 95 figures, 2 tables, accepted for publication in MNRAS