Nucleation temperature (top panel) and nucleation saturation at maximum nucleation rate (bottom panel) as a function of cooling time. The equilibrium temperatures, where the gas phase is in balance with the solid phase, are indicated with short dot-dashed lines. All the species nucleate at temperatures significantly below their equilibrium temperatures because of the inhibition of nucleation at low super-saturation levels. Iron in its pure form nucleates at a lower temperature than the equilibrium of FeO, which would lead instead to direct condensation of FeO onto existing silicates. However, the presence of small amounts of sulfur in the iron (Fe+S) lowers the surface tension enough that iron nucleates before the condensation of FeO.