First row: detection rate vs. spectral type deduced from different S/N thresholds (from left to right: 1, 2, 3, and 4) for ΔT_spot1 (solid) and ΔT_spot2 (dashed) for a 1 M_Earth planet at different orbital periods: lower HZ (black), medium HZ (red), and upper HZ (green). Curves that are not visible are at the 100% level S/N thresholds 1 and 2, and at the 0% level for thresholds of 3 and 4. Second row: mass detection limit with a 50% confidence level for the same criteria (same colour and line code). Third row: same with a 95% confidence level.