We present a simulation of the formation of the earliest Population II stars , starting from cosmological initial conditions and ending when metals created in the first supernovae are incorporated into a collapsing gas-cloud .
This occurs after a supernova blast-wave collides with a nearby mini-halo , inducing further turbulence that efficiently mixes metals into the dense gas in the center of the halo .
The gas that first collapses has been enriched to a metallicity of Z \sim 2 \times 10 ^ { -5 } Z _ { \odot } .
Due to the extremely low metallicity , collapse proceeds similarly to metal-free gas until dust cooling becomes efficient at high densities , causing the cloud to fragment into a large number of low mass objects .
This external enrichment mechanism provides a plausible origin for the most metal-poor stars observed , such as SMSS J031300.36-670839.3 , that appear to have formed out of gas enriched by a single supernova .
This mechanism operates on shorter timescales than the time for low-mass mini-halos ( M \leq 5 \times 10 ^ { 5 } M _ { \odot } ) to recover their gas after experiencing a supernova .
As such , metal-enriched stars will likely form first via this channel if the conditions are right for it to occur .
We identify a number of other externally enriched halos that may form stars in this manner .
These halos have metallicities as high as 0.01 Z _ { \odot } , suggesting that some members of the first generation of metal-enriched stars may be hiding in plain sight in current stellar surveys .