Variability of W7, W26 and W29 over time at 5 GHz. The columns show in order the varying sources W7, W26 and W29 and finally as a control the non-varying resolved source W18 at epochs 1 to 3 (from top to bottom). The contours are at 4, 6, 8, ... times the noise rms for the variable sources and at 4, 12, 20, ... times the noise rms for W18. The noise rms is approximately 15 μJy/beam at all 3 epochs. The beam is plotted for each source on the last row.