The most massive Galactic globular cluster \omega Cen appears to have two , or perhaps more , distinct main sequences .
Its bluest main sequence is at the centre of debate because it has been suggested to have an extremely high helium abundance of Y \sim 0.4 .
The same helium abundance is claimed to explain the presence of extreme horizontal branch stars of \omega Cen as well .
This demands a relative helium to metal enrichment of \Delta Y / \Delta Z \sim 70 ; that is , more than one order of magnitude larger than the generally accepted value .
Candidate solutions , namely , AGB stars , massive stars , and supernovae , have been suggested ; but in this study , we show that none of them is a viable channel , in terms of reproducing the high value of \Delta Y / \Delta Z for the constrained age difference between the red and blue populations .
Essentially no populations with an ordinary initial mass function , including those candidates , can produce such a high \Delta Y / \Delta Z because they all produce metals as well as helium .
As an alternative , we investigate the possibility of the stochastic “ first star ” contamination to the gas from which the younger generation of \omega Cen formed .
This requires the assumption that Population III star formation episode overlaps with that of Population II .
While the required condition appears extreme , very massive objects in the first star generation provide a solution that is at least as plausible as any other suggestions made before .