The EPIC light curves of the nine brightest X-ray sources (pn = green asterisks, MOS1 = black dots, MOS2 = red circles) with 1 ks time bins (top) and 5 ks time bins (bottom). The x-axis is the time elapsed, in seconds, since the beginning of the MOS1 observation, and the XID of each source is quoted to the right of each light curve. χ² tests do not find significant (at the 1% level) and coherent variations in these light curves (XID 6 is found to vary at the 10% level, and XID 2 is slightly better fitted by a trend than by a constant line). (The color version of this figure is available online.)