Measured K-amplitudes (top) and the implied lower limits on M₂ (middle) and q (bottom) for our observed targets. Also plotted in the top panel are the expected K-amplitudes for a 1 M_⊙ star with an 8 M_⊙ companion at the median orbital inclination (solid black line) and the central 64 percent range (shaded region) for a geometric distribution of inclinations; and the maximum expected amplitude for an equal-mass binary (dashed line). The deficiency of targets in the period range 0.5–1 days is due to the different selection methods applied at shorter and longer periods, as is described in the text. None of the systems followed up has spectroscopic M_2, min > 3 M_⊙ or q_min > 1, and in most cases a typical-mass black hole can be ruled out at the 2σ level.