tpfplotter TPF image of TOI-406 as in sector 3. The TESS aperture used to extract the photometry is shown with red squares. Gaia DR3 (Gaia Collaboration 2023) stars are represented as red circles, with sizes proportional to their magnitude. TOI-406 is positioned at the centre (star 1). Star 2 is a G = 16.887 mag star whose contribution to the aperture flux was accounted for by the SPOC pipeline through the calculation of the crowding metric and subtraction of the corresponding percentage (<O.14 percent in all four sectors) of the median flux level to account for dilution. The TPFs of all sectors are shown in Appendix A.