Titanium oxide absorption as a proxy to detect long term variation and activity cycle in Proxima Centauri

Abstract

Stellar activity cycles on magnetically active stars can be estimated by molecular absorption bands. We have previously introduced a molecular index which compares absorptional line strength of the \(TiO\lambda 567nm\) with its nearby continuum has previously been introduced. In this work we use this indicator to evaluation long-term activity variations for Proxima Centauri star, using spectroscopic data from HARPS. The results indicate periodicity with an activity period of \(2873_{-53.9}^{+47.4}\) days, which is similar to the previous measurements from other indicators.