²⁶Mg/²⁴Mg vs. ²⁵Mg/²⁴Mg measured in our sample. Shown are also isotopic ratios from the supernova yields of Nomoto et al. (2006) (Z = 0, blue diamonds; Z = 0.004, green triangles; Z = 0.004 IMF weighted value, red triangle), Tominaga et al. (2007) (Z = 0, black squares) and from the chemical evolution model of Kobayashi et al. (2011) (black X). Shown is also the dilution curve for the isotopes using the model form Ventura et al. (2014). The solar position is shown with a black cross, and our values for Arcturus with a black asterisk.