Signal-to-noise ratio against distance for an Earth-sized 1500 K planet orbiting a Solar-sized and an M-dwarf star. All results are after 5 minutes of integration time and the vertical dashed lines indicate the distance to the associations β Pictoris (purple), TW Hydrae (orange), and η Chamaeleontis (green), respectively. The horizontal gray dashed line represents the considered detection threshold (S/N = 7).