Lightcurves of six of the X-ray flares with optical and/or mIR counterpart discussed in the text. Lightcurves for the full sample can be found in Appendix B, while lightcurves for well defined X-ray flares for which no optical/mIR counterpart was detected are shown in Appendix C. The three panels at the top refer to flares with simultaneous data in all three bands. Within each panel the first two sub-panels, from top to bottom, show the CoRoT lightcurve, normalized to the median of the observed CoRoT flux in the whole exposure (as opposed to the short segment shown), and the Spitzer lightcurve in the IRAC 3.6 μm or 4.5 μm bands (as indicated by the y-axis label and in orange and red, respectively). For both panels a gray line indicate the polynomial intended to represent the non-flaring emission (see text). The ACIS source number of the star and its mIR class are given at the top-left and top-right corners, respectively. The third and fourth panels show the same CoRoT and Spitzer lightcurves, this time subtracted by the non-flaring emission (units given in the right-hand y-axis). The areas shaded in gray indicate our choice for the definition of the optical and mIR flares. The same two panels show the simultaneous Chandra X-ray lightcurve, both binned (black dots with error bars), and using the piece-wise representation discussed in the text (black broken line). Units are shown on the left-hand y-axis. The temporal extension of the X-ray flare, according to our definition, is indicated by a magenta horizontal bar at the top of each panel. The three panels at the bottom show three more X-ray flares with simultaneous CoRoT data, but lacking Spitzer data.