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

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 $TiO\lambda 567nm$ $TiO\lambda 567nm$ 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 ${2873}_{-53.9}^{+47.4}$ $2873_{-53.9}^{+47.4}$ days, which is similar to the previous measurements from other indicators.