Cool Stars: Chromospheric Activity, Rotation, Kinematic and Age

We summarize here our ongoing project of multiwavelength high and medium resolution optical observations aimed at studying the chromosphere of different kinds of late-type stars including pre-main sequence stars (weak-lined T Tauri stars), chromospherically active binaries, flare stars, and young single stars members of stellar kinematic groups. We quantify the phenomenology of chromospheric activity using the information provided by several optical spectroscopic features (from the Ca ii H & K to the Ca ii IRT lines) that are formed at different heights in the chromosphere. In addition, we obtain a better determination of the stellar parameters, spectral type, and possible binarity. With all these information we study the flux-flux and rotation-activity relationships in order to get insights into the mechanisms which drive the solar-like stellar activity.