1. INTRODUCTION

2. SOURCE SELECTION AND DATA REDUCTION  
2.1. Source selection  
2.2. Equivalent Width measurements  
2.3. Correction of EWs  

3.2. Rotation periods and Rossby number

4. DISCUSSION  
4.1. \(R_{\mathrm{H}\alpha}^{'}\) and Rossby number  
4.2. Basal flux and \(R_{\mathrm{H}\alpha}^{+}\)  
4.3. \(R_{\mathrm{H}\alpha}^{'}\) and Light Curves  

5. SUMMARY