Periods and semi-amplitudes of carbon-normal metal-poor binaries from Carney et al. (2003), CEMP-s binaries from Hansen et al. (2016a; excluding their CEMP-r/s stars), and CEMP-no binaries (compilation from this work). HE 1506–0113 (see Fig. C.2) and SDSS J0929+0238 are not shown in this figure since they do not have any derived orbits, HE 2139–5432 is not shown because it either has P <  300 or P ≈ 4000 days (with K ≈ 11 km s⁻¹). The line indicates what would be expected of Keplerian orbits of a 0.8 M_⊙ star with a 0.5 M_⊙ companion, for an eccentricity of 0.3 (typical for the stars in the Carney et al. 2003 sample) under an inclination of 60°.