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Several late-type stars present activity cycles similar to that of the Sun.However, these cycles have been mostly studied in F to K stars. Due to theirsmall intrinsic brightness, M dwarfs are not usually the targets of long-termobservational studies of stellar activity, and their long-term variability isgenerally not known. In this work, we study the long-term activity of two Mdwarf stars: Gl 229 A (M1/2) and Gl 752 A (M2.5). We employ medium resolutionechelle spectra obtained at the 2.15 m telescope at the Argentinian observatoryCASLEO between the years 2000 and 2010 and photometric observations obtainedfrom the ASAS database. We analyzed Ca \II K line-core fluxes and the mean Vmagnitude with the Lomb-Scargle periodogram, and we obtain possible activitycycles of $\sim$4 yr and $\sim$7 yr for Gl 229 A and Gl 752 A respectively.

Long-term chromospheric activity in southern M dwarfs: Gl 229 A and Gl 752 A