Variability factor of sources with significant variability (S > 3) in the energy band of 0.2–5.0 keV plotted vs. the maximum flux. In all the plots of these paper, the symbols characterise foreground starswith red asterisks (), background objects with violet crosses (), sources with counterpart classified as RGBs in 47 Tuc with blue filled circles (), main sequence member of 47 Tuc with green filled circles (), members of SMC with violet filled circles (), and unclassified sources with black filled circles ().