A direct measure of the helium abundances from the near-infrared transition of He i at 1.08 \mu m is obtained for two nearly identical red giant stars in the globular cluster ( catalog Omega Centauri ) .
One star exhibits the He i line ; the line is weak or absernt in the other star .
Detailed non-LTE semi-empirical models including expansion in spherical geometry are developed to match the chromospheric H \alpha , H \beta , and Ca ii K lines , in order to predict the helium profile and derive a helium abundance .
The red giant spectra suggest a helium abundance of Y \leq 0.22 ( LEID 54064 ) and Y = 0.39 - 0.44 ( LEID 54084 ) corresponding to a difference in the abundance \Delta Y \geq 0.17 .
Helium is enhanced in the giant star ( LEID 54084 ) that also contains enhanced aluminum and magnesium .
This direct evaluation of the helium abundances gives observational support to the theoretical conjecture that multiple populations harbor enhanced helium in addition to light elements that are products of high-temperature hydrogen burning .
We demonstrate that the 1.08 \mu m He i line can yield a helium abundance in cool stars when constraints on the semi-empirical chromospheric model are provided by other spectroscopic features .