Light curves from simultaneous observations of TOI-178 by NGTS (green stars) and SPECULOOS-South (purple triangles), described in Sects. 4.1.3 and 4.1.4, respectively. Unbinned data are shown as grey points,and data in 15-minute bins are shown as green stars (NGTS) and purple triangles (SPECULOOS). The observationsoccurred on September 11, 2019 (top panel) and October 12, 2019 (bottom panel). The transit model is shown in black. The position of the odd transit of candidate TOI-178.02 is shown with a dashed red line, the transit of planet g (which corresponds to an even transit of TOI-178.02) is shown with the solid red line, and the transits of planet b are shown with purple lines.